Livestock Health, Management and Production › Animal Health Management › Managing animal health
for trade
Animal Health Management
Managing animal health for trade
Author: Dr Mary-Louise Penrith.
Licensed under a Creative Commons Attribution license.
INTRODUCTION
After completion of this module, students will be expected to understand how animal diseases influence
trade in livestock commodities and understand and explain the role of animal health managers in
supporting this trade. They should be able to apply the knowledge gained to formulate animal disease
control strategies that are functional and appropriate for the circumstances under which they will be
implemented, maintaining the focus on the objectives of animal health management and disease control.
Livestock commodities (i.e. fresh or frozen meat, fresh eggs and milk, raw hides and any other derivatives
that have not undergone further processing) including live animals are traded both nationally and
internationally. International trade in livestock commodities is covered in depth in a series of
dedicated modules. The focus of this module is the impact that animal diseases can have on trade at all
levels and the approaches to managing them to minimise their impact.
Fresh milk is a livestock commodity
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Fresh meat is a livestock commodity
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Animal health management for trade is concerned with ensuring that traded livestock and commodities
derived from livestock are safe in terms of transmission of diseases to animals and humans. It is also
concerned with supporting producers to ensure that there is a steady supply of healthy animals available
for trade, and is supported by both public and private veterinary service providers. Services can range
from primary animal health care and routine surveillance for controlled diseases to herd health
programmes aimed at optimising and monitoring health and production to ensure consistency of quality
as well as supply. Primary animal health care is often supplied, especially in remote rural areas, by
community-based animal health workers (CAHWs) trained and equipped to undertake basic activities like
parasite control, vaccination, and first aid for minor injuries and ailments. To an extent the level of animal
health service provision will depend on the demands and value of the market, but in the end it is the
responsibility of animal health managers to try to ensure that food of animal origin offered for sale for
human consumption is safe and wholesome, whether the food is destined for the highest priced export
markets or the next door neighbour.
To provide background for animal disease control in the context of trade in livestock, the first section
deals with trading of live animals and commodities derived from animals (as opposed to processed
products) insofar as it is affected by infectious diseases. More detail about marketing and trade is
provided in modules dedicated to the subject.
The second section considers approaches to controlling endemic and epidemic transboundary diseases
in the context of the country’s different production systems.
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BACKGROUND TO TRADE IN LIVESTOCK COMMODITIES
Live animals
Live animals pose the greatest risk for transmission of infectious diseases. Cross-border trade in live
animals therefore usually involves some formalities that at the least would be a veterinary certificate of
health but normally include quarantine requirements as well. However, in many countries moving animals
from one area to another also involves formalities. This may be to maintain zones free of particular
diseases and to reassure trading partners that this is being done correctly. For example, South Africa
requires internal movement controls to ensure that cloven-hoofed animals are not moved from the foot
and mouth disease (FMD) protection zone around the Kruger National Park to the rest of the country and
that pigs are only moved from the African swine fever (ASF) control zone in the north-eastern part of
South Africa (mainly Limpopo province) from accredited farms within the zone to designated abattoirs
outside the zone. Even countries without designated free zones may require movement permits in order
to keep track of animals and to prevent spread of diseases from one part of the country to another.
Classification and description of livestock marketing systems

Live animal markets(“wet” markets), shows, fairs, auctions

Agents and speculators

Sale at point of slaughter (abattoir)

Retail outlets other than livestock markets

Private sales – home, roadside

Internet auctions

Import and export marketing agents and systems
Challenges for animal health management
With the presumed exception of internet auctions, which offer a sophisticated way to avoid
unnecessary transport of animals and contact between animals of different origin, marketing
animals can pose a health risk. Even animals bought over the internet might pose a risk if they
are not transported in the correct way.
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Live animal market, Port Bouet, Abidjan, Ivory Coast
Live pig market, Assomada, Santiago, Cape Verde
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Live animal markets or the equivalent (show, fairs, auctions), where large numbers of animals are
brought together under unavoidably stressful conditions, clearly pose a level of risk of disease
transmission that many regard as unacceptable. The H5N1 avian influenza pandemic has led to
at least temporary closure of live poultry markets in some countries, for example China, since it
was evident that infected birds were being offered for sale and that such markets could become
focal points for spread of infection. In developing countries especially, when animals start to
sicken or die and the owner realises that he has a serious disease in his animals the tendency is
to sell off animals as quickly as possible to limit damage. This has been cited as a major reason
for the spread of ASF in Nigeria and has certainly contributed to the fact that the disease has now
become endemic in that country. This tendency is exacerbated by disease control programmes
that involve compulsory culling and disposal of animals without adequate compensation.
Nevertheless, under conditions where live markets offer the only alternative to even higher risk
sale procedures, they present the veterinary authorities with an opportunity to perform inspection
of the animals offered for sale and to take the necessary steps should diseases be detected. The
key to mitigating the risk of live animal markets is that as much veterinary supervision as possible
should be supplied, that the size of the market should be manageable, that the facilities should be
such that reasonable separation of lots from different producers is achieved, and that detailed
records of animals offered for sale are kept to permit rapid tracing to farms of origin if any
outbreaks do occur.
Sale at point of slaughter, i.e. at an abattoir or other area designated for slaughter of animals,
should be safe, as such places can and should be regulated by the veterinary public health
authorities. However, abattoirs have been incriminated as sources of disease, owing to practices
such as the sale of live animals for home slaughter or for purposes other than slaughter. It was
suspected that an outbreak of ASF in Nairobi in 1994 may have originated from pigs brought from
an area close to the border with Uganda to an abattoir in Nairobi and being sold live to clients
instead of being slaughtered. There is also a possibility that animals in the incubatory phase of a
disease may show no clinical signs or lesions at inspection but infected product will be released
to the market. To prevent this happening in the case of an asymptomatic bovine infected with
bovine spongiform encephalopathy (BSE) being slaughtered, there is a requirement for the
removal of specified risk materials (SRMs), which include tonsils, distal ileum, brain, eyes, spinal
cord, skull and vertebral column. The rest of the carcass is safe, although animals known to pose
a high risk (e.g. old dairy cows born before the feed ban) are not passed for human consumption.
Lymph node removal is generally considered to reduce risk of disease transmission and may be
recommended for other diseases as well, e.g. FMD.
Sale of live animals through retail outlets other than livestock markets is generally confined to
companion animals including birds that are sold through pet shops. Particularly in the case of
imported birds and reptiles, it is important that the veterinary authorities ensure that the proper
quarantine procedures have been complied with before these animals are disseminated to the
public.
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Private sales and sales through agents are activities that are often impossible for the veterinary
authorities to monitor, and the risk can therefore be high. Professional agents who work under
contract to their clients are unlikely to place their livelihoods at risk by breaking the laws
pertaining to animal movements and sales. On the other hand, livestock speculators are rife,
particularly in the rural areas in the developing livestock sector. They provide a means of selling
animals beyond the local market for producers who have no transport to carry animals to the
distant urban markets, and therefore make an important contribution to the economy of such
areas, even if the prices offered are frequently less than fair. However, their role in the spread of
disease is undisputable, since they move from one producer to another and can also move
infected and sick animals to new areas, selling them off on the way if they look as if they will not
survive the journey.
Sales transactions between private individuals probably pose the lowest risk, provided that both
parties are properly informed and that sick animals are not sold or bought. Purchase of animals
directly from breeders is recommended as a safe way to acquire animals, provided the breeders
are reputable and their facilities are visited by veterinarians (private or state) on a regular basis.
In the informal livestock sector breeders may be less reliable. As previously indicated, during
disease outbreaks that result in heavy mortality the temptation to sell off animals that appear
healthy but may be incubating disease is extremely high, and the danger of this practice must be
a prominent part of farmer education as well as public awareness programmes.
Illegal roadside sale of pigs during an African swine fever outbreak, Volta, Ghana
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Trade in commodities derived from animals
Trade within countries
At local level, apart from live animals, the usual edible commodities derived from animals that are
traded are fresh meat, milk and eggs. Their safety in rural communities is far from assured. In
poor communities, dead animals or commodities derived from them may be sold, posing a risk to
human health. Most cases of human anthrax in developing countries can be traced to the
butchering and consumption of animals that have died of anthrax, a practice that not only often
results in human illness but also results in environmental contamination with anthrax spores
because the carcasses are not disposed of in the recommended way. Roadside sales of meat
and dead animals (e.g. animals that have been hunted), often observed in developing countries,
may not only result in the sale of diseased meat but the meat may have spent a long time at high
temperatures and have been exposed to flies and other sources of contamination. The trade in
bushmeat at both local and international level is globally regarded as a major problem that must
be addressed urgently as it threatens biodiversity, food security in communities that for centuries
have exploited wildlife for food in a sustainable way, and animal and human health. Informal sales
of animal commodities may result in transmission to people of zoonoses like anthrax, pig
tapeworm (Taenia solium), trichinellosis, bovine tuberculosis, brucellosis, salmonellosis and Rift
Valley fever (RVF). These can result not only from butchering animals that have died of disease,
but also lack of meat inspection, lack of pasteurisation of milk, and inadequate cooking. Diseases
like anthrax, classical and African swine fever and avian influenza may also be transmitted to
scavenging animals, in particular pigs, cats and dogs, as well as wild species, by careless
disposal of remains. Public education is the only practical way to address the problem, since
many rural areas lack animal health officers, but veterinarians are ultimately responsible for
ensuring that accurate information about how diseases are spread and acquired is available to
extension officers and other workers in rural communities. Skins and hides are non-edible
commodities that are also traded, and while generally regarded as safe, an exception has proven
to be transmission of anthrax spores in hides; occasional cases of anthrax in humans have been
recorded that were traced to skins used in the manufacture of drums.
In the formal sector, where commodities derived from farmed animals are eventually sold through
retail outlets like butchers, dairies and supermarkets, the concept that there must be reassurance
of safety of the product from ‘farm to fork’ or ‘stable to table’ is widely accepted. Animal health
managers are responsible for the part of the value chain that extends from the farm to the
abattoir, milk or egg collection point, i.e. the point at which they cease to be closely associated
with the animal. Once the commodities enter the retail chain they usually become the
responsibility of the municipal health authorities, although this may vary between countries.
However, the chain is seen is an unbroken entity and to ensure this there are increasing
requirements for traceability that would enable the final product to be traced back with certainty to
the farm and even the animal of origin. Sometimes the entire value chain takes place on the farm,
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or meat products are sold directly from the abattoir and in these cases the veterinary authorities
might need to oversee the entire process. Abattoirs have served as a source of disease through
the sale of offal not designated for human consumption as well as meat and organs condemned
for various reasons, and the improper disposal of waste from the slaughter process. Most
countries have legislation regulating these practices, and the difficulty lies in ensuring that the
legislation is implemented. Sale at abattoirs should be restricted to the sale of edible products
from animals that have undergone ante- and post-mortal inspection. The products should be
handled and packaged hygienically and records kept of the transactions in the form of receipt
copies or other sales records.
International trade in livestock commodities
When livestock commodities are exported or imported, regulatory mechanisms come into play
determined by the importing countries guided by international norms and standards. These are
discussed in much more detail in modules on marketing and trade, but the situation is briefly
summarised here.
Rules and structures
Animal production is regulated by national legislation, which varies according to the country. It
may determine where and under what conditions animals may be kept and what may legally be
fed to animals. Animal health legislation has an impact on production, as it provides for the
registration and use of veterinary medicines, which is vital for international trade. Livestock and
livestock commodity trade is subject to regulation at both national and international levels.
At the international level, the World Trade Organisation (WTO) provides member states, through
the Sanitary and Phytosanitary (SPS) Agreement, guidelines for fair trade in animal and plant
commodities. The World Animal Health Organisation or Office International des Épizooties (OIE)
is the body designated by the WTO to develop guidelines and standards for trade in animals and
animal commodities. These guidelines are available through the Terrestrial Animal Health Code
(TAHC) and the Aquatic Animal Health Code available on the OIE website, www.oie.int. The food
safety standards for products destined for human consumption are set by a joint committee of the
World Health Organization (WHO) and the Food & Agriculture Organization of United Nations
(FAO), the Codex Alimentarius Committee. Some countries or trading blocs, in spite of WTO and
OIE membership, impose their own standards that are generally higher than those of the OIE and
make access to their high value markets very difficult for developing countries, especially in
regions like sub-Saharan Africa where many major transboundary animal diseases are endemic.
Many countries tend to follow the EU standards. This has various reasons. Firstly the OIE
standards differ for different diseases and therefore a number of chapters in the codes have to be
consulted in order to export meat, whereas the EU standards are simpler to follow. Secondly,
some veterinary authorities would not like to be seen as imposing a ‘lower’ standard. Thirdly,
countries that export to the EU are virtually forced to apply similar standards as importing meat
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under less rigorous provisions could jeopardise their status. In addition to standards set by
trading blocs and individual countries, international companies and alliances are increasingly
setting private industry standards. This situation provides challenges to the official international
standard-setting bodies, which need to harmonise their standards as far as possible with market
requirements reflected in the private standards without compromising their role in facilitating trade
for all their member countries.
There are initiatives among regional bodies in sub-Saharan Africa to support intra-regional trade
and to find ways to overcome the differences in animal health status that exist between member
countries. COMESA (Common Market for Eastern and Southern Africa) has 19 members in
southern and eastern Africa, from Egypt to Swaziland; SADC consists of 15 member countries in
southern Africa, several of which are also members of COMESA, and EAC (East African
Community) is a community consisting of Uganda, Kenya and Tanzania, the first two of which are
members of COMESA and the last of SADC. There is also a West African bloc, ECOWAS
(Economic Community of West African States). COMESA, SADC and EAC are exploring the
establishment of a tripartite body with a focus on trade policies that will permit free movement of
agricultural products among member states subject to some form of certification.
At national level, livestock trade is regulated by laws covering the movement and transport of
animals, the slaughter of animals, and all aspects of veterinary public health and food safety.
Animal welfare is increasingly becoming important for trade in animal commodities as well as live
animals, particularly in the higher priced markets. At national level, guidelines for the welfare of
animals may be provided through Welfare Codes as well as legislation. The OIE is actively
involved in developing standards for animal welfare and has so far developed seven standards
relating to terrestrial animals, six of which provide for aspects of trade and disease control
(transport of animals by land, sea and air, slaughter of animals for human consumption, killing of
animals for disease control purposes and control of stray dog populations). Animal welfare is
the subject of a dedicated module.
Risk mitigation for livestock commodities
The OIE provides guidelines for risk assessment for import and export in Chapter 2.1 of the
TAHC. This is discussed in more detail in modules covering tools for animal health
management including risk assessment. The concept supports the requirement of the SPS
Agreement that prohibition of the importation of agricultural commodities must be scientifically
defensible. It can also be used in support of Article 4 of the SPS Agreement that provides for
countries to achieve freedom from infection for commodities by different pathways (principle of
equivalence). Risk assessment can be used to evaluate whether these pathways result in
commodities posing only an acceptable level of risk.
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Classification of commodities and products (i.e. commodities that have undergone further
processing) derived from animals, ranked in the order of the level of risk they may pose for
transmission of pathogens that threaten animal or human health:

Live animals

Semen, ova, embryos

Fresh or frozen products (meat, raw milk, eggs, offal/carcass meal, manure, raw hides,
hair and fibre, serum and tissues used for biological products)

Processed products (processed meat, milk and dairy products, rendered carcass meal,
tanned hides)
Within these categories there are variations in the level of risk posed. For example, hides in
general pose a lower level of risk than fresh meat. The simplest way to mitigate the risk posed by
a commodity for a particular disease is to derive it from an area that is demonstrably free of that
disease, and this is the criterion on which most of the OIE standards are based. However, it is
recognized that countries with few resources may find it difficult if not impossible to create and
maintain zones that are free of diseases that are endemic in the region. A particular problem
facing the SADC countries in this respect is the fact that the most trade-sensitive disease, FMD,
is endemic in African buffalo. Achieving separation between buffalo and cattle involves the use of
game-proof fences, which are contrary to principles of biodiversity conservation and are not an
option in the vast transfrontier conservation areas that have been established in the region. The
problem experienced by livestock farmers in such areas is highlighted in a DVD entitled ‘Beauty
and the Beef’.
Increasingly, in order to overcome the problem of trade embargoes on livestock products from
developing countries owing to the endemic presence of serious transboundary diseases within
their borders, attention is turning to commodity-based trade. It has been demonstrated that
certain commodities are unable to sustain or transmit infection, even if they originated from an
animal that was actually infected, owing to the properties of the pathogen itself or to its
distribution in the animal. For example, deboned beef from which the lymph nodes have been
removed is unable to transmit FMD, because the post slaughter conversion of muscle glycogen to
lactic acid provides an unfavourable environment in which the FMD virus is unable to survive, and
standards could be developed to ensure the safety of the commodity. Article 8.5.25 in the chapter
on FMD in the TAHC (2011) provides standards for export of beef from vaccinated animals in an
infected area that, if adopted by importing countries, would largely address this requirement. The
tissues in which the prions that cause bovine spongiform encephalopathy (BSE) are likely to be
present have been identified. Provided that these specified risk materials (SRMs) have been
removed from slaughtered cattle, the meat is safe for consumption. The prions are also not
present in milk. Various pork products subjected to a lengthy curing process have been found to
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be unable to harbour the ASF and classical swine fever (CSF) viruses in spite of their ability to
persist in meat for long periods. There are many other commodities for which standards could be
developed. Animal health managers need to be aware of this and to be able to evaluate, at least
within broad limits, whether the level of risk posed by particular commodities that traders wish to
import is acceptable, and also to provide science-based arguments for the safety of products
destined for export. It is important to emphasise that commodity-based trade does not open the
door to sourcing products from sick animals. Animals that do not pass the usual ante- and postmortem inspection will not enter the food chain. It does, however, invalidate the argument that
because animals incubating a disease but showing no signs might accidentally enter the food
chain, animals cannot be sourced from an infected area, thus excluding large numbers of
livestock producers in Africa from international and sometimes even regional markets. This
viewpoint is strengthened by recent research that indicated that shedding of FMD virus prior to
development of clinical signs may occur only briefly.
Both COMESA and SADC have adopted commodity-based trade in principle and are busy with
various initiatives related to feasibility and cost-effectiveness, recognizing that it is likely to be the
only approach that will permit free trade in livestock commodities among countries ranging from
those whose animal disease status is unknown but likely to be poor to countries like Namibia that
are able to meet the EU conditions for export to their markets. At the same time, countries that
have invested considerable resources in establishing export zones are seeking equitable
solutions for large numbers of poor livestock owners who are excluded from the export market
because they are not within the export zones, and this is also likely to involve commodity-based
trade. The concept is also likely to support trade in products derived from the sustainable
exploitation of wildlife, which will be necessary in order to ensure that biodiversity conservation
provides benefits for communities living in or adjacent to conservation areas (the DVD referred to
above provides a good insight into the situation).
Animal identification and traceability
High value markets for livestock commodities have stringent requirements for animal identification
and traceability, especially for cattle. Identifying their animals has obvious advantages for the
producers. It enables good record-keeping to monitor production and it also increases the
possibility of recovering stolen livestock. Identification and traceability support animal health
management by enabling better follow-up during outbreaks as well as proper registration of
animals during interventions such as vaccination campaigns and surveillance for diseases, and
may be a national requirement. However, the demand for traceability throughout the marketing
chain by trading partners in industrialised countries may require resources that are simply not
available in poorer countries. It is usually the responsibility of the animal health authorities to
decide which systems are appropriate to their situation (for example individual animal
identification vs herd or batch identification) and whether a large investment in identification will
be justified in terms of the expected financial gains through trade. Further information about
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animal identification and traceability is available in a module on that subject as well as in relevant
chapters of the TAHC (2011).
Sheep and cattle identified by ear tags
Certification
One of the most important issues for international trade is the provision of certification for animals
and products destined for export. The OIE provides standards and guidelines for the importation
of live animals, semen, ova and embryos, and some of their derivatives such as fresh and frozen
meat, hides, and fibres. According to these guidelines the competent veterinary authority of a
country is responsible for certification that the traded goods pose no more than an acceptable risk
for the transmission of pathogens that are harmful to animal or human health. Guidelines for
certification are provided in Chapters 5.1 and 5.1 and model certificates in Chapters 5.10-12 of
the TAHC. The Codex Alimentarius provides food safety standards for a very large variety of
processed products including products derived from animals, but these standards refer only to
safety in terms of human pathogens. In assessing the risk to animal health posed by certain
commodities, veterinarians need to use their own technical knowledge of the way important
animal pathogens behave to decide whether those commodities are likely to harbour them or not.
In order to provide credible certification of the health status of the animals and of the area from
which they originated, countries must have surveillance plans and systems in place that provide
assurance that as much information as possible about the health status of the country is available
to the veterinary authority. The surveillance system should be backed up by a reliable laboratory
diagnostic service. The OIE Terrestrial Manual for Diagnostic Tests and Vaccines available online
at the OIE website provides an overview of laboratory tests for all the important animal diseases.
Increasingly there is insistence that laboratories should provide quality assurance through a
quality management system that complies with the international standard for analytic and testing
laboratories, ISO/IEC 17025, developed by the International Standards Organisation (ISO) based
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in Geneva. There is also increasing pressure for laboratories to be accredited for compliance with
this standard by an internationally recognised body.
The act of processing livestock products often destroys any pathogens that may be present and
renders the products safe. Thus, the heat process used in canning meat will inactivate most
pathogens, excluding prions. Some but not all methods of curing pork inactivate the viruses that
cause ASF and CSF. However, the actual safety of such products depends upon the processing
having been carried out correctly. Thus, carcass meal rendered at the temperatures and duration
required to destroy the BSE agent is safe regardless of whether it inadvertently contains SRMs
from an infected animal, but this will only hold true if the processing was entirely reliable as
certified. Process certification may not be within the scope of the competent veterinary authority
owing to lack of specialised knowledge. This is a problem that will need to be addressed for the
unreserved adoption of commodity-based trade. Certification is the subject of a dedicated
module.
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CONTROL OF ANIMAL DISEASES TO SUPPORT ANIMAL
PRODUCTION AND TRADE
Animal disease control measures to support production and trade fall into two main categories: those
measures required to deal with emergency situations created by the outbreak of a serious transboundary
disease that was not previously present in the affected country or area, and those required to prevent
diseases that are endemic from having deleterious effects on either livestock production or trade.
Control of endemic livestock diseases
Animal production in developing countries, particularly in Africa, is often severely constrained by the
presence of animal diseases that cause high mortality, like peste des petits ruminants (PPR), ASF and
Newcastle disease (ND), or result in poor performance, like the tick-borne diseases and trypanosomosis.
The result may be a lack of animals to satisfy the country’s own needs as well as the lack of a surplus to
export. Concerns are also raised about zoonotic diseases, which are more easily transmitted under
conditions of close contact between humans and animals and where milk and meat are handled and
consumed without being processed in any way that will destroy pathogens.
Vaccination of cattle against anthrax, South Africa (photograph courtesy of Anabela Manhiça, Mozambique
Institute for Agricultural Research)
In sub-Saharan Africa, a number of serious transboundary diseases (FMD, RVF, PPR, CBPP, contagious
caprine pleuropneumonia, bluetongue, sheep and goat pox, African horse sickness (AHS), ASF, ND, to
name a few) are present endemically, usually in several countries. For some of these, particularly those in
which maintenance of the agent occurs in wild animals, like FMD and ASF, eradication at least in the
short term is not a realistic option. In order to trade in livestock commodities, these countries are required
to adopt control measures that will convince trading partners that livestock commodities originating from
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these countries pose no more than an acceptable level of risk for transmission of endemically present
transboundary diseases.
Routine disease control
Routine disease control activities are aimed at attaining or maintaining good animal health status
and supporting animal production.
Routine disease control activities may include:

Programmes for control and/or eradication of specific diseases

Vaccination campaigns (procurement, storage, distribution)

Monitoring the results of disease control activities

Provision of treatment/clinical services by the state

Routine surveillance for diseases including changes in epidemiological patterns.
Control (managing the disease) and eradication (eliminating the disease) programmes require the
participation of the livestock owners. Such programmes may be compulsory or voluntary,
depending upon the nature of the disease and the available resources. Diseases that are
frequently the target of sustained control programmes are erosive diseases that affect production
and/or are zoonoses like brucellosis, bovine tuberculosis, rabies, tick-borne diseases and
trypanosomosis, as well as transboundary diseases like FMD, contagious bovine
pleuropneumonia (CBPP), and the swine fevers. Depending upon the disease, approaches
include testing and slaughter of positive animals, vaccination, and vector control. All of these
activities have cost implications, and in order to be successful must be well planned and
implemented. Before embarking on a control programme, it is important to identify the target
population and then to decide upon a strategy that will be both effective and achievable with the
available resources. It will be necessary to determine what laboratory diagnostic capacity is
available to support the programme if laboratory tests are involved. The wide spectrum of
laboratory techniques described for each disease in the OIE Manual for Diagnostic Tests and
Vaccines may not be available in the local laboratory!
Vaccination campaigns need careful planning and management. Most vaccines are fragile and
require that the cold chain be maintained from manufacture to administration to the animal. Even
so-called thermostable vaccines are usually thermotolerant but will not withstand prolonged
storage at high temperatures. The procurement process for vaccines should ensure that they are
delivered well in advance of their expiry date, in a way that will ensure maintenance of the cold
chain. They should be stored in such a way that the recommended temperature (usually 2-8°C) is
reliably maintained. Arrangements must be made to ensure that the vaccines can be kept cold
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throughout the distribution and administration process. Vaccines that have spent a hot day in an
uninsulated container on the back of a vehicle in the sun are not likely to be effective and the
whole effort will have been wasted. On the other hand, allowing liquid vaccines to freeze will
usually render them ineffective.
Vaccination of dogs against rabies, Catuane, Mozambique
Whatever the nature of a control programme, monitoring its progress is extremely important and
the monitoring strategy should be built into the programme from the beginning. Effective
monitoring will permit identification of problems and enable changes of strategy to resolve them,
and will also enable programmes that are clearly not working to be modified or abandoned. After
control has been achieved, a surveillance programme should be maintained in order to intervene
early at any sign of resurgence of the disease.
The provision of treatment and clinical services by government veterinarians when this is not
linked to official control programmes is a matter for debate. In countries where no or very limited
private veterinary services are available, or where a large proportion of the livestock producers
are subsistence farmers who cannot afford private services, interventions by government
veterinarians may be necessary. There is no doubt that the provision of primary animal health
care enhances the image of state veterinarians and creates an opportunity to improve disease
surveillance. Various attempts have been made to distinguish between “public” and “private”
goods in the provision of veterinary services, the former involving animal diseases that are a
threat to public health or the national economy, for example highly contagious diseases, while the
latter refers to diseases that are in the farmer’s own interests to control. Greater private sector
involvement has been advocated, but the practicality of this will of course depend upon the
availability of private veterinary service providers as well as the ability and willingness of livestock
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producers to pay for the services. The provision of primary animal health care by trained
community animal health workers (CAHWs) is an option that has proved beneficial when properly
managed. Well trained CAHWs, who are members of the communities they serve, have proven
invaluable in remote areas and among nomadic pastoralists who would otherwise have no access
to veterinary services. They can also make significant contributions to surveillance for disease, as
has been demonstrated in a study in northern Tanzania.
State-sponsored dipping programmes provide opportunities
for surveillance and vaccination, South Africa
Options for managing endemic transboundary animal diseases to support trade in
livestock commodities
As indicated above, the SPS Agreements of the World Trade Organisation are designed to
prevent importing countries from unfairly using non-tariff trade barriers, e.g. risk of importing an
unwanted animal disease, unless they can demonstrate that the risk posed by the imports is real
and does not already exist within their borders. This means that they may not discriminate against
countries that have an equivalent health status, but does not prevent them from prohibiting
imports from countries that have a less satisfactory status in terms of serious livestock diseases.
The requirement that an exporting country should have the same animal disease status as the
importing country is widely accepted in industrialised countries. Since most of these are free from
all of the serious transboundary animal diseases, it could theoretically be impossible for countries
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where one or more of those diseases occurs endemically to access the advantageous markets
for livestock products afforded by the industrialised countries. In response to the need to provide
market access for developing countries, the SPS Agreement recognizes the principle of
equivalence, which permits export from countries that are not free of certain diseases provided
that they can satisfactorily demonstrate that the commodities pose no more than an acceptable
level of risk. In practical terms, this means that the commodities should originate from an area
that is free of the specified disease/s, or should be demonstrably unable to transmit the specified
infectious agent/s.
The OIE recognises geographical zones that are free for FMD, rinderpest (now globally
eradicated), CBPP, AHS, PPR and CSF. Countries can also apply for a rating for the level of risk
that they pose for BSE. In some SADC countries zonal freedom from FMD without vaccination
has been achieved by using fences to effect physical separation between African buffalo and
domestic livestock combined with buffer zones with vaccination and observation. The principle
that a zone can be free of a specific disease with vaccination is accepted and is applied in Brazil,
but to achieve freedom with vaccination it is necessary to be able to distinguish between
vaccinated and unvaccinated animals. This is currently difficult for FMD within the SADC region,
since the test used to distinguish between vaccinated and infected animals is regarded as
insufficiently sensitive for the SAT virus types, but purification of the antigen used in vaccine
production has greatly increased the sensitivity of the assay.
It has been accepted by the OIE that for certain diseases it will be virtually impossible to achieve
geographically free zones, for example ND and avian influenza. A “new” concept,
compartmentalisation, has been proposed, in which a production unit may be recognised as
being free of a specific disease, allowing export of livestock commodities originating from that unit
to take place. The concept is based on strict biosecurity of the unit, which applies also to the feed
source, transportation of animals for slaughter, and the slaughter facility. Once a compartment
has achieved official recognition by the competent veterinary authority (the OIE does not provide
official recognition for compartments) of freedom from one disease, this status can obviously be
extended to other diseases. It is recognised that the control measures that countries like Kenya
and South Africa adopted for pig farms not long after ASF was identified as a disease entity in the
first half of the last century effectively resulted in compartmentalisation of pig farms. The
guidelines for zoning and compartmentalisation are defined together in the TAHC and there is a
chapter on the application of compartmentalisation.
The commodity-based trade approach acknowledges that it may be difficult if not impossible for
many developing countries with endemic transboundary diseases to achieve country or zonal
freedom in the short term and that compartmentalisation will initially, at least, apply only to a few
commercial producers able to achieve a high level of biosecurity in their production units. In spite
of initial concerns that acceptance of commodity-based trade might reduce the impetus to
eradicate transboundary diseases which is the stated aim of the OIE, it is increasingly accepted
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that if sub-Saharan Africa is to benefit from its livestock resources in ways that could change lives
there has to be an alternative that will improve their access to global markets. Lack of
competitiveness in terms of livestock numbers, quality and resources has been cited as likely to
exclude sub-Saharan African countries from global livestock markets, but these impediments may
be susceptible to change once trade in livestock commodities actually becomes possible because
there are no longer definitive bans on particular areas.
Managing animal disease emergencies
Definition of an animal disease emergency
An animal disease emergency refers to any change in the status of a disease that can have
potentially disastrous consequences in terms of animal health, human health, and/or the national
economy.
Objectives of animal disease emergency management
Managing an animal disease emergency, which usually implies an outbreak of a highly
contagious disease, is never easy, even with the best contingency plans in place and all the
resources needed to implement them. Success can never be assured, because in the end the
outcome depends not only on the actions of the veterinary department but also on the behaviour
of producers and traders, which in spite of legislation may be impossible to monitor and control. It
is therefore imperative to prevent disease emergencies as far as possible by ensuring good
surveillance for animal diseases and identifying and managing risks, for example the
management of airport and harbour swill.
If, in spite of all efforts to prevent it, an animal disease crisis occurs, the objectives of managing it
include some or all of the following:

Limiting damage to livestock production when a disease emergency occurs
o
Economic losses to livestock producers
o
Economic losses in the satellite sectors – loss of trade, jobs
o
Economic losses at national level – costs of importation to replace locally produced
product, loss of export trade

Protecting public health

Protecting the environment
The Food & Agriculture Organization of the United Nations (FAO) has developed, under the
EMPRES (Emergency Prevention System for Transboundary Animal and Plant Pests and
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Diseases) Programme (http://www.fao.org/ag/againfo/programmes/en/empres.html), a tool known
as Good Emergency Management Practice (GEMP), available on CD and on the FAO/EMPRES
website as a multi-media programme. It promotes the concept of a Code of Practice in dealing
with animal disease emergencies.
GEMP in animal health is defined as follows: ‘the sum total of organised procedures, structures
and resource management that lead to early detection of disease or infection in an animal
population, prediction of the likely spread, prompt limitation, targeted control and elimination with
subsequent re-establishment of verifiable freedom from infection in accordance with the
International Animal Health Code’
[http://www.fao.org/AG/AGAInfo/programmes/en/empres/gemp.html]. The details of GEMP are
covered in other modules.
Practical approach to resolving disease emergencies
Key issues that need to be explored when preparing a strategy for dealing with disease
emergencies:

Identification of problem areas and risk factors (i.e. factors that place the success of disease
emergency management measures at risk)

Identification and training of key personnel (include people outside animal health services)

Integration of stakeholders in disease emergency management

Awareness campaigns
Resources for animal disease emergency management
A variety of resources are required for managing animal disease emergencies:

Information
o
Information about the disease
o
Background information about livestock numbers and distribution and production
systems
o
Information from field services
o
Information from laboratory services

Human resources

Financial resources
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
Infrastructure, equipment, supplies

Appropriate contingency plans and Standard Operating Procedures (SOPS)
Failure to have one or more of these resources in place is likely to lead to failure to contain the
disease emergency.
Information
The veterinary department should have access to up-to-date reference works on infectious and
parasitic diseases, in order to understand the aetiology and epidemiology, as well as how to
confirm the diagnosis. The OIE Manual for Diagnostic Tests and Vaccines, available on the OIE
website (www.oie.int) provides basic information about each disease as well as details on the
samples required for diagnosis. However, not all of the disease descriptions contain sufficient
information about the epidemiology to be adequate for each disease as it occurs in different parts
of the world. One way of ensuring ready access to information is to incorporate it in the
contingency plan. When preparing the contingency plan (see GEMP and other modules on
disease control), the introductory chapter should describe all the important aspects of the
disease, and should be updated as necessary, using the most up-to-date reference works
available.
A database giving the most up-to-date livestock figures available, with distribution maps and
some information about production systems is invaluable for planning actions and identifying high
risk areas.
Information from the field services in the affected area and also in unaffected areas is crucial for
planning the response in both.
The contingency plan should contain the information about what diagnostic tests can be
performed by the laboratory and what type of samples are required, but contact with the
laboratory is essential to ensure that there are no obstacles to the performance of the diagnostic
tests (for example lack of reagents, equipment not functional, or absence of crucial staff
members), and if there are problems, what alternative arrangements have been made to
overcome them.
Human resources
The contingency plan will have identified the human resources required for implementation. The
emergency team, which will usually include members of the state veterinary service as well as the
laboratory, is of vital importance in the first response to investigate the outbreak and initiate an
epidemiological inquiry. Assistance may be required from other departments, for example
extension officers, police and army officers, and the media. The necessary mechanisms to enlist
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their services should be in place to avoid bureaucratic delays. Their activities will need to be
coordinated through a Joint Operations Committee or equivalent.
Lack of the necessary human resources is a serious constraint for control of disease
emergencies. Often the veterinary services of developing countries are thinly spread. It is
important that the contingency plan should specify who is responsible for what, and should also
indicate who will substitute officials who are unavoidably not available when the emergency
happens. Contact details for the emergency team members should be readily accessible,
preferably at the front of the contingency plan, and updated as necessary.
It must also be recognised that a disease emergency takes priority over all other activities, and
that undesirable as it may be, it offers animal health officers a unique opportunity to gain
experience that should not be missed in favour of some routine activity that can be interrupted
without serious consequences.
Financial resources
An emergency fund should be available for dealing with animal disease crises, from which the
necessary funds can be released rapidly. Ensuring that such a fund exists is an important
responsibility of the veterinary services, who should supply the technical inputs that will convince
the decision-makers of the importance of rapidly accessible finance.
A mechanism for rapid release of such funds is vital. It is understandable that in government
organisations measures for release of funds are often cumbersome in order to ensure that all the
correct authorisations are in place. In the case of an emergency fund, arrangements must be in
place to ensure that there is no question of waiting for an indispensable signature while the
diseases sweeps unchecked across the country.
Infrastructure, equipment and supplies
The provision of infrastructure is with some exceptions not within the capability of the veterinary
services, but it is important that the contingency plan should identify any shortcomings in this
respect and propose ways in which they may be overcome.
Equipment includes vehicles and sampling equipment, including the means to keep the samples
in a good state of preservation until they reach the laboratory. If stamping out of animals is to be
part of the control plan or there are large numbers of dead animals to be disposed of safely,
earth-moving equipment may be required. The contingency plan will specify the equipment
needed.
Supplies will include protective clothing, disinfectants, and any other consumables (specimen
jars, preservatives, swabs, etc.).
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Contingency plans and Standard Operating Procedures
These should be available and should be relevant to the situation in the country. They should also
be tested, preferably by performing simulation exercises, and updated and modified as
necessary. The GEMP guidelines of FAO/EMPRES include a concise summary of the nature and
structure of contingency plans.
In addition to the resources mentioned above, the following are important resources:

Discipline and good practice at all levels in the livestock industry

Political will
Achieving these through dialogue and education must be part of the long-term strategy of the
veterinary services, since, if they are not in place when an animal health crisis occurs, the
consequences will inevitably be severe.
Conventional approaches to disease emergencies
The conventional approach to a disease emergency created by the outbreak of a highly contagious
disease has traditionally been to eradicate it by stamping out, i.e. the compulsory slaughter of all infected
and in-contact animals, sometimes of all the animals of the affected species within a defined area or
radius. The slaughtered animals are destroyed by some process that prevents their consumption and
dissemination, usually deep burial or burning or both. This is accompanied by quarantine of the affected
area or areas, with strict movement control of animals and products out of the area. Disinfection of
infected premises follows slaughter, and restocking is permitted after a prescribed period. In order to
obtain their cooperation, livestock owners are usually compensated for the animals slaughtered. After
discovery of a focus, the veterinary authorities attempt to trace back any movements into and out of the
area that occurred before measures were applied, and to stamp out any other potential or actual foci that
are detected in this way.
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Eradication by stamping out. Stamping out results in many carcasses for disposal by burning or burial
Until recently, this was the approach advocated by international organisations such as the OIE, the FAO
and the EU. Increasingly, however, a combination of strengthening of public opinion against the mass
killing of animals, the undoubtedly serious environmental implications of the disposal of vast numbers of
carcasses, and the enormous expense involved are making it necessary to explore other options. A
further reason to explore other options is the fact that expensive stamping out operations often fail to
contain the outbreak and cause more damage to producers than the disease itself, particularly in
developing countries.
Reasons why conventional control measures fail
In order to succeed, control measures such as quarantine, movement control and stamping out have to
be applied immediately and rigorously, since the objective is to contain the agent within the designated
area or cordon, and the escape of even one infected animal may foil that purpose. It is extremely difficult
under any conditions, but particularly with limited resources, to apply measures sufficiently rigorously to
ensure containment within the focus.
Factors that contribute to the failure of measures are the following:
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
Failure of the early warning system, so that the “index” case is not the first case, and other foci of
infection exist elsewhere undetected. Tracing back animal movements may result in the discovery
of these foci or may fail to do so, depending on the level of cooperation of the population and also
their level of information.

Tardiness of response, giving time for spread of the infection. Producers who know that drastic
measures are going to be applied are likely to take advantage of any lapse of time to sell as many
animals as possible.

Failure of movement control. When an outbreak of disease occurs, and in particular when the
method of controlling it is compulsory slaughter, the incentive for owners to move animals to
avoid the control measures is usually stronger than the ability to prevent animal movement. Road
blocks, if efficiently operated, will prevent at least overt movement of animals along the roads, but
these do not offer the only way out of the infected area. Furthermore, there are reasons why road
blocks cannot always operate efficiently. Firstly, the sheer volume of road traffic in most countries
makes it impractical to thoroughly search every vehicle that passes. Much of the philosophy of
outbreak control is based on the measures developed for rinderpest, which among domestic
livestock primarily affects cattle. Cattle are large and visible, but the smaller species and parcels
of meat are much easier to conceal. Secondly, in developing countries where officials are poorly
paid, the incentive to allow animals to pass may be greater than the incentive to prevent them.
Road blocks are not always effective in preventing movement of animals and animal products

Inefficient disposal of carcasses of infected animals. Particularly if large numbers of animals are
involved, disposing of carcasses can present serious problems. Incineration of carcasses is
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recommended but the costs are high if the process is to be effective. Deep burial, accompanied
by treatment with quick lime, is the alternative. Either way, a suitable site for disposal must be
selected, and the immediate focus of infection may not offer the necessary conditions. Moving
carcasses is hazardous from the point of view of spreading infection. Furthermore, in poor
communities the destruction of large amounts of edible meat is not easily accepted, and in many
instances carcasses have been disinterred and consumed or even sold for consumption. Telling
people who are in the habit of eating animals that die that eating the meat will endanger their
health is unlikely to have any effect, particularly if it rapidly proves to be untrue.

Failure to compensate owners for compulsory slaughter of animals. Prompt payment of marketrelated compensation may provide the necessary incentive for cooperation, particularly if the
disease is of such a nature that it is obvious that large numbers of animals are going to die
anyway. However, developing countries are often unable to pay compensation at all, let alone at
market-related rates. The application of stamping out without compensation or with inadequate
compensation is most likely to result in spread of the disease, since it will encourage clandestine
movement and sales that, for reasons given above, will be impossible to prevent. Even when
adequate compensation is available, problems such as bureaucratic delays in payment will result
in future non-compliance.

Factors that prevent resumption of productive farming as soon as possible. These include
requirements for excessively long ‘empty’ periods before re-stocking, lack of suitable animals for
re-stocking, lack of funds for re-stocking, and unrealistic requirements for resumption of farming
activities, for example provision of new housing and infrastructures according to unachievable
standards.
Careful consideration is therefore necessary before embarking on an eradication campaign based on
stamping out the infection. This should be clearly reflected in the contingency plan. There are
circumstances when it may be feasible, for example if the index case is genuinely the index case, the
source of the infection is clear (for example, contact with wildlife), and the affected herd or flock is well
isolated, with relatively few animals that need to be killed and plenty of space to dispose of the carcasses.
For countries with a significant export market for meat, and therefore a strong incentive to regain disease
free status as soon as possible, stamping out may be the only option. However, even in this case, the
probability of success must be weighed against that of failure, and a cost-benefit analysis should be
undertaken to ensure that the expected revenues from import will offset the cost of the control operation,
or that the losses of revenue due to failure to control the outbreak will exceed the cost of control.
If there is a probability that the considerable resources invested in eradicating the outbreak will be wasted
because they will fail, alternative control strategies should be considered.
One option is to limit the number of animals that have to be slaughtered by some form of emergency
vaccination to contain the disease, usually by ring vaccination around the affected focus. In order to
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regain disease free status, it has been recommended that the animals that were vaccinated should be
slaughtered to eliminate them from the population, but the necessity for this is open to question. When
stamping out is not an option, for example in the case of rare zoological collections that are not infected,
selective vaccination may be permitted. Vaccination of the total population has also been used as an
alternative to stamping out, for example in some HPAI-infected countries where it was deemed
impossible to achieve the requisite level of stamping out in backyard flocks.
Alternative control strategies
For most diseases, an obvious alternative to eradication by stamping out is vaccination, usually limited to
the area around the outbreak, but sometimes considerably wider. Although the costs involved in
purchasing and administering the vaccine may be high, the advantage is that the animals, other than
those that are infected and die of disease, are available for sale and consumption, and do not have to be
disposed of in an expensive and environmentally unfriendly manner.
The decision to vaccinate depends upon the availability of sufficient quantities of an efficacious vaccine,
the funds required to pay for it, and the importance of the export market on which vaccination may have a
negative effect. Another factor that contributes is the perception that vaccination as a means of control is
an admission of defeat, will result in large numbers of carriers of the disease, and ensure that the disease
becomes endemic. The fact that vaccination has played a central role in the eradication of rinderpest is
apparently overlooked. Insistence upon the importance of “disease freedom without vaccination”, in other
words the demonstrable absence of infection, has induced in many countries a reluctance to vaccinate
that does not take local conditions into account, including the need to keep a fragile economy dependent
upon livestock production alive and even to ensure household food security.
The obvious disadvantage of vaccination as an outbreak control measure is the fact that antibodies take
some time to develop and attain protective levels, usually about two weeks after the first vaccination. This
means that all efforts to contain the infection inside the focus must be made during the critical period,
and, as indicated above, this may be very difficult to achieve.
Concern about the effect of vaccination on exports will naturally depend on the importance of the export
market. Reluctance to import vaccinated animals or their products stems from the fact that until recently it
was not possible to distinguish between antibodies resulting from vaccination and those resulting from
infection. The development of marker vaccines offers a way to overcome this problem in the future, but
for most diseases marker vaccines are not yet available, and progress in this field is hampered by the
negative attitude of highly developed countries to vaccination, even in the face of serious outbreaks.
However, this may change as eradication by stamping out becomes less and less acceptable. A
simulation study performed after the 1997/1998 outbreak of CSF in the Netherlands, which was brought
under control by stamping out of affected and neighbouring unaffected herds, concluded that emergency
vaccination would have been the best option, with the advantage of sparing healthy pigs.
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The perception that vaccination encourages a carrier state and merely serves to disguise circulating
infection is unfortunate, and ignores the important contribution that vaccination has made to disease
control and even to eradication. Certainly the use of vaccination implies that either the infection or the risk
of infection is known or suspected to be present. The infection, or risk of it, does not result from the
vaccine, since the overwhelming majority of vaccines are based on pathogens that have been rendered
incapable of causing disease, and reversion to virulence is extremely unusual, although it has been
recorded in rare instances. Animals protected by vaccine, when exposed to natural infection, are usually
unable to shed infective amounts of the pathogen and thus do not infect other animals, unless vaccination
has not been effective or a breakdown of immunity occurs for some reason. Effective vaccination permits
normal production to continue in the presence of infection and, in spite of misgivings on the part of trading
partners, the derivatives of such animals pose little realistic risk for transmission of disease. In
populations in which a high level of immunity is maintained by vaccination, and in the absence of
reservoirs of infection in wildlife or vectors, the disappearance of the pathogen, resulting in eradication of
infection, is a real possibility. In the case of diseases for which reservoirs exist in wildlife populations, the
risk of infection will always be endemic, but with proper protection of domestic livestock, including by
effective vaccination, there is no reason why the disease itself should become endemic in domestic
animals. There are, however, requirements for successful vaccination, such as the suitability of vaccines
(able to protect against the agent causing the outbreak), quality of vaccines, and a delivery system that
ensures that the majority of the target population of animals will be effectively vaccinated; this usually
includes respect for the cold chain. Vaccination as a disease control tool is dealt with in greater detail
in a dedicated module.
The decision to vaccinate as an emergency control measure therefore depends not only upon cost and
feasibility, but also on whether eradication of the infection without vaccination is a realistic and feasible
option.
Sometimes vaccination may not be possible, either due to costs, or, in the case of some diseases, e.g.
ASF, the lack of a vaccine. In these cases, given that large-scale eradication by stamping out is also not
feasible, alternative measures must be considered.
In principle, the aim of emergency control measures is to reduce the size of the susceptible population as
rapidly as possible. Both stamping out and various vaccination strategies have precisely this aim. Other
ways to reduce the susceptible population include the supervised sale for slaughter of healthy animals
through official outlets as rapidly as possible, and the protection of unaffected herds by the institution of
biosecurity measures that will prevent contact with the pathogen.
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Permanent isolation of pigs in accredited farm, African swine fever control area,
Limpopo province, South Africa
With pathogens that require direct contact for transmission, such as ASF virus, which will be used as an
example here, protection of animals through simple but strict biosecurity measures that require the full
cooperation of the owner will effectively remove such animals from the susceptible population. These
measures when applied to ASF consist of maintaining the pigs confined, strictly limiting access to the
herd, disinfection of clothing, footwear, and hands for people who have to have contact with the pigs, not
feeding swill unless it has been boiled for at least 30 minutes, and avoiding any other practices that might
result in infection. These include sharing boars, equipment, feed sacks, and anything else that could
possibly be contaminated. If the owners of affected herds are agreeable, slaughter of the remaining incontact animals should be undertaken. Compensation in the form of nucleus breeding stock is more
economical than monetary compensation, and is usually acceptable to owners. The sale of carcasses or
meat from infected herds is not acceptable, but owners can be permitted to use some of the meat for own
consumption provided that it is thoroughly cooked. Under some circumstances, pigs that have apparently
survived the outbreak may be allowed to live, although not to leave the farm, since animals that recover
fully from ASF apparently do not become long-term carriers. Such pigs might remain infective for up to a
month after recovery, and they should remain on the farm and not be slaughtered or their meat
disseminated for at least three months to ensure that they do not infect other pigs.
The same principles apply to other diseases that rely on direct transmission or where airborne
transmission is possible only over short distances. If a long-term carrier state is known or suspected to
exist, as is the case for many bacterial diseases (e.g. bovine, tuberculosis, bovine brucellosis, glanders)
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animals known to have been exposed to infection that survive the outbreak should be slaughtered, or at
least separated and subjected to testing and slaughtered if infection is confirmed.
Creating awareness during an animal health crisis
Livestock producers need to be informed as quickly as possible when their animals are at risk owing to an
outbreak of a highly contagious disease. The most effective way to reach as many people as quickly as
possible is via the public media (radio, television, newspapers). In this way the public will also be
informed so that they will understand measures such as road blocks that may in some way affect them.
This should be followed up by the dissemination to producers and other stakeholders in the industry of
more detailed information on how to protect animals and on the measures that are to be applied. For this
purpose the help of the agricultural extension services can be enlisted. Commercial farmers may be able
to be contacted through producer organisations; the existence of farmer organisations at all levels is
extremely helpful for disease control support.
The message should be clear, simple and easily understood, and not unnecessarily alarmist. It must also
be technically correct and truthful. As indicated above with regard to the safety of meat from dead animals
for human consumption, at least some of the producers will have sufficient knowledge to recognize
untruths, and the entire message will then lose all credibility.
Pig farmers receive a pamphlet with photographs to assist in recognising
African swine fever and a poster with simple instructions as to how to prevent it (Ivory Coast)
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Raising awareness about highly contagious diseases of animals should not only happen in response to
an emergency. Awareness about diseases is essential for good surveillance, and, if an emergency
occurs, it makes the public awareness campaign much easier, because there is a foundation of
knowledge on which to build. Theoretically, at least, if sufficient awareness has been created, animal
disease emergencies should be very rare events indeed.
Recovering from an animal disease emergency
The actions required in recovering from an animal disease emergency are the following:

Re-stocking after extensive losses due to mortality and/or control measures. The Terrestrial
Animal Health Code of the OIE proposes “infective periods” for diseases during which re-stocking
should not be undertaken, usually based on double the maximum incubation period of the
disease. In practice, re-stocking should not commence until it is fairly clear that the outbreak is
over in that particular area. However, the imposition of unrealistically long bans on re-stocking is
unacceptable and can lead to the collapse of the sector, since people have to make a living and
are likely to turn to other activities if they cannot resume farming within a reasonable period. The
use of sentinel animals at no more than 10% of the normal stocking rate may be recommended to
avoid serious losses if an error of judgement has been made and infection is present. Sentinel
animals should be fully susceptible, and should be observed for a period that exceeds the
incubation period of the disease. If at the end of that period the animals have neither developed
clinical signs nor antibodies, the premises can be regarded as safe. The selection of sources of
animals for re-stocking should be careful, particularly in developing countries where donors may
offer animals. The animals should be from a source that is guaranteed to be free of unwanted
diseases, and should be of a breed and type suitable for the farming system. The replacement of
indigenous breeds with high quality exotic breeds with nutritional and management requirements
that are far beyond the means of the recipient to provide will not be helpful and will compound the
losses suffered during the outbreak. Such animals are also prone to disasters such as death as a
result of eating toxic plants through lack of previous experience of them.

Risk mitigation: it is important to try to identify the cause/s of the outbreak in order to prevent
recurrence due to the same cause. If the actual cause can be pin-pointed and eliminated, that is
certainly the first prize. Very often it is not possible to determine with precision the exact cause of
the outbreak, and very often as well the apparent cause is not the real cause, which will then be
overlooked. It is therefore helpful to examine the circumstances under which the outbreak
occurred and to decide whether they can be improved to reduce the probability of further
outbreaks. This will probably involve intensifying awareness on the part of producers and
stakeholders so that, even if they are not able to alter the system within which they operate, they
are able to eliminate high risk factors, for example by boiling swill, reducing contact with wildlife,
or improving biosecurity in general.
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
Building on lessons learned: this is an ongoing process that involves working with stakeholders to
achieve better prevention and control, and identifying and rectifying weaknesses in the system
(for example by improving surveillance, exerting better control over the fate of waste from ports of
entry and abattoirs, intensifying communication with stakeholders, repairing fences, or revising
vaccination programmes).
FAQS
1. What is the difference between a livestock commodity and a livestock product?
A commodity refers to a derivative of an animal that has not undergone further processing. For
example, fresh or frozen meat is a commodity, corned beef, cured hams and canned meats are
products; raw milk and eggs are commodities, once they have been pasteurised or otherwise
heat treated they are products; raw hides are commodities, leather is a product.
2. What are the main impacts of animal diseases on trade?
The two most important impacts that animal diseases can have on trade are firstly lowered
production or raised mortality that reduces quantity and quality of livestock and livestock
derivatives available for trade, and secondly trade bans imposed by potential trading partners to
prevent the introduction of diseases via livestock and livestock commodities.
3. Are there standards and guidelines for trade in livestock and livestock products, and if so,
who decides on them?
There are standards and guidelines for international trade. The World Organisation for Animal
Health (OIE) is mandated by the World Trade Organization (WTO) to develop and publish
standards for trade in live animals and in commodities derived from live animals. The Codex
Alimentarius, a joint committee of the World Health Organization and the Food & Agriculture
Organization of United Nations, is mandated by WTO to develop standards for food safety; these
apply to commodities and products that are destined for human consumption. Standards for trade
within countries are usually provided for in national legislation.
4. Can the OIE force countries to implement their standards?
The OIE cannot enforce standards as it has no legislative powers; countries use the standards (or
their own standards, which may be more or less exacting than the OIE standards) to determine
their requirements for veterinary certification of livestock and livestock commodities entering their
countries.
5. Who is responsible for managing animal diseases for trade, the government or the
livestock producers, or both?
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Managing animal diseases is really a joint responsibility. The state normally takes responsibility
for the management of serious transboundary animal diseases that can threaten other countries
or that must be prevented from being introduced, as well as diseases that pose a very serious
threat to human health. Producers are in general responsible for managing endemic diseases
whose main effect is on production and productivity. In developing countries the lines are often
blurred because the majority of livestock producers are smallholder and subsistence farmers who
do not have the resources to manage the health of their animals adequately.
6. What are the most important diseases in southern Africa that have to be managed for
trade?
The diseases endemic in the region that have the greatest potential to affect export are foot and
mouth disease, African swine fever, African horse sickness and highly pathogenic avian influenza
in ostriches; outbreaks of Rift Valley fever, especially in South Africa, also had negative effects on
trade. A range of infectious diseases in the region can affect productivity, including the tick-borne
diseases, trypanosomosis, blueongue, anthrax, bovine brucellosis, bovine tuberculosis, lumpy
skin disease, contagious bovine pleuropneumonia, Newcastle disease and peste des petits
ruminants, to name only the more important ones; some of these, in particular Rift Valley fever,
anthrax, brucellosis and tuberculosis, can also affect human health.
7. Why is foot and mouth disease such a major problem for international trade when it is
neither highly fatal to cattle nor a zoonosis?
FMD was eradicated at great expense from Europe and other parts of the developed world,
where it caused considerable production losses. In high producing dairy herds in cool damp
climates, for example, it is a much more severe disease than in cattle kept extensively in warm
dry areas. It can also be a very severe disease in intensively kept pigs. In the recent SAT2
outbreak in Egypt there has been high calf mortality, presumably owing to the replication of the
virus in the heart muscle, which rarely occurs in sub-Saharan Africa. This explains the reluctance
of countries that have eradicated FMD to run the risk of re-introducing the virus.
8. If deboned, de-glanded beef is accepted as being a safe commodity because it is unable to
transmit FMD, what else, if anything, would be needed to enable poor farmers in infected
areas to export their beef to high value markets?
Apart from export-rated abattoirs to slaughter the cattle and prepare the meat according to
international standards, the quality and quantity of cattle would need to be appropriate for the
market. The infected areas are generally characterised by low productivity and poor quality of
cattle, and this would need to change if a market that required a sustainable supply of high quality
meat became available.
9. Which other diseases are of concern when it comes to exporting meat?
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Theoretically the main diseases of concern are those whose agents can survive for long periods
of time in the carcass after the animal has been slaughtered, e.g. the swine fevers, but in practice
any disease in food animals tends to have a negative effect on trade, even diseases like
contagious bovine pleuropneumonia that are not transmitted in meat.
10. Are the fears of introducing animal diseases through meat realistic?
There are certainly many well documented cases of diseases like foot and mouth disease and the
swine fevers in particular being introduced into countries via infected meat. What usually happens
is that infected meat is fed to pigs as swill or is improperly disposed of and becomes available to
scavengers. Recent disease events where the source of infection has been fairly convincingly
established have pointed to galley waste from ships rather than legally imported meat as the
problem. The risk from legally imported meat for human consumption is relatively low.
11. Is quarantine an effective way of ensuring that diseases are not introduced with live
animals
That depends on the quarantine protocol and the quarantine facility, as well as the diseases
themselves. Provided that the quarantine protocol ensures that the animals are able to be
isolated for long enough for any disease of concern that they are incubating to manifest before
they are released and the quarantine facility is secure and well managed and does not permit
contact between different batches of animals, prevention should be effective. However, there are
some diseases that are difficult to test for or that have very long incubation periods that might be
able to remain unnoticed and only manifest later when the animals have been released.
Examples of such diseases are glanders in horses and contagious bovine pleuropneumonia.
12. What is an animal disease emergency?
Animal disease emergencies usually involve diseases with high morbidity and high mortality in
animals but can sometimes involve diseases where relatively few animals may be affected but
there is a high case fatality rate in humans (rabies). They can result from the introduction of an
exotic disease to a country, e.g. when classical swine fever was introduced into South Africa in
2005 it caused a disease emergency, or from the spread of a disease from an area where it is
endemic to an uninfected area, e.g. the outbreaks of foot and mouth disease in Kwazulu-Natal in
South Africa that emerged in 2011 and in previously free zones in Botswana in 2010, or from the
sudden occurrence or increased incidence of a disease due to particular conditions, like Rift
Valley fever, e.g. in East Africa in 2006 – 2007 and in southern Africa in 2010 – 2011.
13. When there is a disease emergency in food animals, does all trade in the meat of that type
of animal stop?
Some countries will immediately place a ban on all the meat from the species of animals affected
by the outbreak, but there are mechanisms that will allow trade to continue from areas or facilities
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that pose a negligible risk for transmission of the disease. For example, outbreaks of FMD in
infected areas in countries with free zones from which meat is exported do not (or should not)
affect trade from the free zones. Compartments that are recognised by the veterinary authority
and trading partners as being free of particular diseases are (or should be) able to continue to
trade regardless of the status of those diseases elsewhere in the country. For some diseases
(Newcastle disease, avian influenza and, most recently, foot and mouth disease) trade can
continue as long as there has been no outbreak during a specified period of time within a 10 km
radius of the facility where the animals were raised/kept and the facility where the meat was
processed.
14. What does surveillance for animal diseases involve?
Surveillance for animal diseases means having a system in place that will allow early signs of a
disease outbreak or a significant increase in the incidence of a disease to be identified. The
system requires the involvement of everyone involved in animal production and health because
the veterinary authorities cannot be everywhere all the time and they need the support of the
animal breeders and everyone else involved in the value chain. The topic of surveillance for
animal diseases is covered in detail in a dedicated module.
15. Why is stamping out still used as a disease control measure when it causes so much
disruption?
Stamping out is often seen as the only way to ensure that an outbreak is eradicated as quickly as
possible, since the alternatives leave animals that might spread the disease alive. Countries or
zones that are recognised as free of a disease but experience an outbreak can regain free status
more rapidly if they opt for eradication by stamping out. For diseases for which no vaccine exists,
there is a perception that stamping out is the only alternative. The main reason why stamping out
is still undertaken is therefore to allow countries to resume trade as quickly as possible.
16. What are marker vaccines?
Marker vaccines are vaccines that enable vaccinated animals to be distinguished from naturally
infected animals because by testing the animals it is possible to differentiate between the
antibodies resulting from vaccination and those resulting from infection.
17. What role can the media play in influencing the effect of disease on trade in animal
products?
The media can play a positive or negative role. When there is an outbreak of animal (or human)
disease the public needs to know about it, particularly if they are likely to be inconvenienced by
measures such as road blocks, or need to have their companion animals vaccinated, or certain
products are going to disappear from the shelves of their butchery or supermarket. However, the
media should be informed via press releases from the veterinary authority that provide the
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technically correct information about the disease and do not leave room for the media to
capitalise on the possibility of raising panic. The novel H1N1 pandemic influenza in 2009 was a
sad example of the negative effect that the media can have. In spite of repeated requests from
WHO, OIE and pig industries worldwide not to refer it as ‘swine ‘flu’ this was ignored by the media
and the result was huge losses to pig industries in spite of the fact that people, not pigs,
transmitted the disease. The USA alone lost $1.2 billion in revenue from pork exports when 29
countries banned their pork at the start of the outbreak.
REFERENCES
1. Allport, R., Mosha, R., Bahari, M., Swai, E. and Catley, A. 2005. The use of community-based
animal health workers to strengthen disease surveillance systems in Tanzania. Revue
scientifique et technique, Office International des Épizooties, 24: 921 – 932.
2. Allsopp, B.A., Babiuk, L.A. & Babiuk, S.L. 2004. Vaccination: an approach to the control of
infectious diseases. In Coetzer, J.A.W. & Tustin, R.C. (ed) Infectious Diseases of Livestock,(2nd
edn), Vol.2 Cape Town, Oxford University Press: 239-247.
3. Anon 2011. Manual of diagnostic tests and vaccines for terrestrial animals. www.oie.int
4. Anon, 2011. Terrestrial Animal Health Code. www.oie.int
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
Chapter 2.1 Import risk analysis

Chapter 3.1 Veterinary services

Chapter 3.2 Evaluation of veterinary services

Chapter 3.3 Communication

Chapter 4.1 General principles on identification and traceability of live animals

Chapter 4.2 Design and implementation of identification systems to achieve animal
traceability

Chapter 4.3 Zoning and compartmentalisation

Chapter 4.4 Application of compartmentalisation

Chapter 5.1 General obligations related to certification

Chapter 5.2 Certification procedures

Chapter 5.3 OIE procedures relevant to the Agreement on the Application of Sanitary and
Phytosanitary Measures of the World Trade Organization
Livestock Health, Management and Production › Animal Health Management › Managing animal health
for trade

Chapter 6.1 The role of veterinary services in food safety

Chapter 6.2 Control of biological hazards of animal health and public health importance
through ante- and post mortem meat inspection

Chapter 6.9 Responsible and prudent use of antimicrobial agents in veterinary medicine

Chapter 8.5 Foot and mouth disease
5. Bradley, B. & Verwoerd, D.W. Bovine spongiform encephalopathy. In Coetzer, J.A.W. & Tustin,
R.C. (ed) Infectious Diseases of Livestock,(2nd edn), Vol.2 Cape Town, Oxford University Press:
1408-1421.
6. Brückner, G.K. 2011a. Managing the risks of disease transmission through trade: a commoditybased approach? Revue scientifique et technique, Office International des Épizooties, 30: 289 –
296.
7. Brückner, G.K. 2011b. Ensuring safe international trade: how are the roles and responsibilities
evolving and what will the situation be in ten years’ time? Revue scientifique et technique, Office
International des Épizooties, 30: 317 – 324.
8. Catley, A., Blakeway, S. and Leyland, T. 2002. Community-based animal health care. A practical
guide to improving primary veterinary services. ITDG Publishing, London.
Catley, A. & Leyland, T. 2001. Community participation and the delivery of veterinary services in
Africa. Preventive Veterinary Medicine, 49: 95-113.
9. Charleston, B., Bankowski, B.M., Gubbins, S., Chase-Topping, M.E., Schley, D., Howey, R.,
Barnett, P.V., Gibson, D., Juleff, N.D. and Woolhouse, M.E.J. 2011. Relationship between clinical
signs and transmission of an infectious disease and the implications for control. Science, 332:
726 – 729.
10. Honhold, N., Douglas, I., Geering, W., Shimshoni, A., Lubroth, J. 2011. Good emergency
management practice: the essentials. A guide to preparing for animal health emergencies.
11. Kaeslin, E. 2011. FAO’s work on sustainable use of bushmeat: Engaging in international policy
processes and finding practical solutions at local level. Proceedings of the International
Symposium on ‘The relevance of community-based natural resource management (CBNRM) to
the conservation and sustainable use of CITES-listed species in exporting countries’, Vienna,
Austria, 18-20 May 2011: 37-40.
12. Mangen, M.-J.J., Jalvingh, A.W., Nielen, M., Mourits, M.C.M., Klinkenberg, D. & Dijkhuizen, A.A.
2001. Spatial and stochastic simulation to compare two emergency-vaccination strategies with a
marker vaccine in the 1997/1998 Dutch Classical Swine Fever epidemic. Preventive Veterinary
Medicine, 48: 177-200.
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13. Mebus, C.A., House, C., Ruiz Gonzalvo, F., Pineda, J., Tapiador, J., Pire, J.J., Bergada, J.,
Yedloutschnig, R.J., Sahu, S., Becerra, V. & Sanchez-Vzcaino, J.M. 1993. Survival of foot-andmouth disease, African swine fever, and hog cholera viruses in Spanish Serrano cured hams and
Iberian cured hams, shoulders and loins. Food Microbiology, 10: 133-143.
14. Mebus, C., Arias, M., Pineda, J.M., Tapiador, J., House, C. & Sanchez-Vizcaino, J.M. 1997.
Survival of several pork viruses in different Spanish dry-cured meat products. Food Chemistry,
59: 555-559.
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P.S. & Shamaki, D. 2010. Spatio-temporal dynamics of African swine fever outbreaks in Nigeria,
2002 – 2007. Transboundary and Emerging Diseases, 57:330-339.
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foot-and-mouth disease associated with international trade in deboned beef. Transboundary and
Emerging Diseases, 57: 115 – 134.
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Tustin, R.C. (ed) Infectious Diseases of Livestock,(2nd edn) Vol.2, Cape Town, Oxford University
Press: 1088-1119.
18. Penrith, M.-L. & Thomson, G.R. 2004. Special factors affecting the control of livestock diseases in
sub-Saharan Africa. In Coetzer, J.A.W. & Tustin, R.C. (ed) Infectious Diseases of Livestock,(2 nd
edn) Vol. 1, Cape Town, Oxford University Press: 171-177.
Rich, K.M. & Perry, B.D. 2011. Whither commodity-based trade? Development Policy Review, 29:
331 – 357.
19. Rubira, R. 2007. Disease control options for emergency animal diseases – necessary yet
sensitive elimination of disease. Veterinaria italiana, 43: 333 – 348.
20. Smith, K.M., Anthony, S.J., Switzer, W.M., Epstein, J.H., Seimon, T., Jia, H., Sanchez, M.D.,
Huynh, T.T., Galland, G.G., Shapiro, S.E., Sleeman, J.M., McAloose, D., Stuchin, M., Amato, G.,
Kolokotronis, S.-O., Lipkin, W.I., Karesh, W.B., Daszak, P. & Marano, N. 2012. Zoonotic viruses
associated with illegally imported wildlife products. PLoS one, 7: e29505.
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Food Animal Production and Health Guidelines 4, Rome, Food & Agriculture Organization of the
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22. Thomson, G.R., Leyland, T.J. & Donaldson, A.I. 2009. De-boned beef – an example of a
commodity for which specific standards could be developed to ensure an appropriate level of
protection for international trade. Transboundary and Emerging Diseases, 56: 9-17.
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23. Thomson, G.R., Perry, B.D., Catley, A., Leyland, T.J., Penrith, M.-L., Donaldson, A.J. 2006.
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G.G.M. & Penrith, M.-L. 2004. International trade in livestock and livestock products: the need for
a commodity-based approach. Veterinary Record, 155, 429-433.
Websites
OIE
www.oie.int
FAO
www.fao.org
FAO EMPRES
http://www.fao.org/ag/againfo/programmes/en/empres.html
FAO GEMP
http://www.fao.org/AG/AGAInfo/programmes/en/empres/gemp.html
WTO
www.wto.org
EU
http://ec.europa.eu/trade/
COMESA
www.comesa.int
SADC
www.sadc.int
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