Management of Pig Health
John J. McGlone, Ph.D.
Pork Industry Institute
Texas Tech University
Approaches to Ensure Pig Health
Biosecurity – keep diseases out



In-coming breeding stock
Wildlife (rodents, birds)
Feeds and biologicals
Disease Prevention




All-in-all-out & pig flow (breaks cycle)
Sanitation -- kill pathogens
Vaccination
Sub-therapeutic antimicrobials
Therapy
Biosecurity
Rule #1 put as much distance as
possible between your pigs and other
pigs
Rule #2 isolate, test and acclimate incoming breeding stock – do not allow
entry if infected
Rule #3 Control flow of people, pigs,
feed and equipment
Sanitation
The pathogen cycle




Clean, new facility
Pigs shed bacteria
Room cleaned 99%
Pathogens build-up over time
Effective sanitation (see book Table 20-1)


Remove all organic matter
Sanitize at a minimum (killing 99% of bacteria)
Heard Health Program
Veterinary-approved
Disease surveillance



Necropsy ill pigs
Blood collection
Fecal, urine, skin scrapings collections
Slaughter check






Liver
Lungs
Snout
Intestine
Skin
Kidney
Heard Health Program
Euthanaisa



Blunt trauma for piglets
CO2 for piglets, too
Penetrating captive bolt for larger pigs
Vaccinations
Antimicrobials
Giving injections
Injections
Pig Disease Categories
Diseases we do not want to get
(that we know about)
Diseases that are regulated by the US
government with an eye towards
eradication
Other diseases to manage
2
Pig diseases we do not want (by exotic
disease entry or by bioterrorism)
Hog Cholera
Hoof and Mouth
African Swine Fever
3
Hog Cholera
Classic Swine Fever
Viral; single stand of RNA
Family: Togaviridae, Genus: Pestivirus
Same family as BVD
USA eradication was from 1962-1976
Has not been eradicated from Europe
(note The Netherlands).
4
Hog Cholera
Infected pigs shed virus for 10-20 days
Can be transmitted in utero
Feeding garbage exacerbates the
spread; leading to the outlaw of this
practice in many states.
6-day incubation period; Respiratory;
enteric; anorexia; hunched; ataxia;
leukopenia
5
Foot (Hoof) and Mouth
6
Foot (Hoof) and Mouth
A picornavirus
Family: Picornaviridae; Genus:
Apthovirus
(Aptha, in Greek means
vessicles in the mouth)
RNA virus; 7 serotypes
Can infect pigs, cattle, sheep & goats
Aerosol is highly contagious
6
Foot and Mouth
Can be transmitted in semen; not the fetus
North and Central America is free; South
America, Africa & Asia are infected
3-5 day incubation period
Vessicles in mouth and between toes;
Sharp fever, abortion; skin lesions leading to
sluffing of tissue
7
African Swine Fever
8
African Swine Fever
DNA-containing virus; Family: Iridovirdae
Only pigs (including wart hogs and the like)
are susceptible; ticks may be carriers
High fever & mortality; respiratory distress;
Hemorragic disease
May resemble Hog Cholera
Little antibody formation -- no vaccine
8
Vaccines?
Foot and Mouth -- yes
Hog Cholera -- yes
African Swine Fever -- no
What else is out there???
9
Diseases that are regulated by
the US government
Pseudorabies
Brucellosis
You can be validated as free from
these by state agencies
Feral pigs are major carriers of
these and other diseases
10
Pseudorabies
Aujeszky’s Disease
11
Pseudorabies
Aujeszky’s Disease
Viral; Herpesviridae of the subfamily
alphavuirus; DNA
While pigs are the only “natural” host, it
infects all farm animals and vermin
All pigs can be infected; suckling pigs
are least affected
Transmitted by aerosol, fluids, incl.
semen
11
PRV
2-4 day incubation period
Nervous symptoms among younger pigs
(ataxia) and respiratory and reproductive
symptoms among older pigs (G-F & sows)
Mortality can be 100% among piglets
Farrowing rate is reduced due to abortions
and many stillbirths are observed
PRV
Few gross lesions; respiratory & GI
tracts are affected
Genetically-engineered vaccine allows
vaccination titers to be distinguished
from natural infections
States & USA quarantine the herd as a
part of the eradication program
Brucellosis
Bacteria -- Brucella suis
Infects pigs and humans (a different
organism infects cattle -- Brucella abortus -with only a little cross over)
Nearly eradicated in the USA (TX still
infected)
Venereal disease of swine; Reproductive
failures, especially abortions
12
Major Classes of Production
Diseases (ones some chose to live
with)
Respiratory
Enteric
Reproductive
Parasitic
Metabolic
Respiratory
PRRS
Atrophic Rhinitis
Mycoplasmal pneumonia
Swine influenza
Actinobacillus pleuropneumoniae
PRRS
PRRS
Lelystad virus
In 1997, 68.5% of USA farms were
seropositive
Farrowing rate declines by 50%
Stillbirths & preweaning mortality & growing
pig mortality increases by 300%
(1-3 pigs/litter born dead; 2 to 6 % mortality
in each of nursery & G-F)
PRRS
Modified live vaccine offers poor
protection
No effective treatment
Widespread problem; not solved by
SEW or any measure other than “all-inall-out and wait” or depopulate
Atrophic Rhinitis
Atrophic Rhinitis
Caused by 2 organisms:
Bordetella bronchiseptica causes a nonprogressive form of AR
Progressive (severe) AR is caused by
toxigenic Pasteurella Multocida
When both organisms are present, the
AR is especially symptomatic
Atrophic Rhinitis
Atrophic Rhinitis
Severe turbinate atrophy, bloody &
crooked noses, followed by increased
incidence of respiratory tract lesions
and infections
Genetic predisposition is possible
Caustic air environments exacerbate the
symptoms
SEW may help eliminate the bugs
Atrophic Rhinitis
Production set-backs are the most
costly
Vaccines are available for BB & PM
Sulfamethazine is effective, but banned
in some countries; a host of partially
effective antibiotics are available
Suggest: Depopulation
Mycoplasmal pneumonia
Mycoplasmal pneumonia
Also called enzootic pneumonia
Bacteria: Mycoplasma hyopneumoniae
Nose-to-nose contact spreads the organism
Highly prevalent in the the USA, Europe,
Australia and most modern pig countries
Lungs have lesions; secondary infections;
performance set-backs
Mycoplasmal pneumonia
Several antibiotics are available; all are
only partially effective
SEW may help prevent its spread
Suggest: Depopulate
Actinobacillus
pleuropneumoniae
Actinobacillus
pleuropneumoniae
Also called Haemophilus
pleuropneumoniae
Bacteria of the name: Actinobacillus
pleuropneumoniae
Widespread distribution
Economic cost is associated with rapid,
high mortality, rather than only
production set-backs
Actinobacillus
pleuropneumoniae
Brought on by stress; can be acute or
chronic
Rapid fever, foamy, bloody respiratory
tract discharge; death within 36 hours;
tract is inflamed and bloody;
Rapid, high levels of certain antibiotics
can be effective
Suggest: Clean up or depopulate
Swine influenza
Also called swine flu, caused by a virus;
Influenza A virus (Orthomyxoviridae
family); Different serotypes;
Birds and other mammals may carry or
become infected by the virus -including humans
Mild stress brings out symptoms
Swine influenza
Swine influenza
Significant respiratory symptoms,
including dog-barking type of coughing
Fever is mild; 1-3 day incubation period
No specific treatment is available; make
sure water is available
Pneumonic Pasteurellosis
From Pasteurella multocida (gram
negative coccobacillus)
See Atrophic Rhinitis for more details
Often isolated and labeled the cause of
death following acute respiratory
distress
Many antibiotics are available
Enteric Diseases
TGE
E. coli
Swine dysentery
Ileitis (proliferative enteropathies)
Clostridium
Coccidia
Rotavirus
TGE
TGE
Transmissible Gastro Enteritis
Viral: Coronavirus; RNA
Severe enteric symptoms; there is a
Porcine Respiratory Coronavirus (PRCV)
that cross reacts with TGE
TGE
18 h to 3 day incubation period; then
severe scours; 50-100% of piglets will
die; fewer older pigs; sows vomit;
watery to yellow scours with a foul odor
Destruction of intestinal epithelium;
pigs unthrifty for life
Feed-back of dead pigs is best
Strikes more in winter
E. coli
E. coli is a common intestinal bacteria;
pathogenic E. coli is the enteric organism;
Enteric Colibacillosis; many serotypes
Gram negative, flagellated rods; bacteria
produces endotoxin
Symptoms like TGE; lower death loss and it
should respond to antibiotics if treated early
Swine dysentery
Swine dysentery
Bloody scours; mucohemorrhagic
diarrhea
Bacteria: Treponema hyodysenteriae; 7
serotypes known
Bloody scours, especially in G-F pigs
Fever; deaths if untreated
Several antibiotics are available
Suggest: depopulation
Ileitis (proliferative
enteropathies)
Hemorrhagic
Necrotic
Ileitis (proliferative
enteropathies)
Several diseases in this category; some
bacterial, others of unknown cause
Campylobacter genus is involved
Sudden deaths; some times bloody
scours; slow growth
Some antibiotics are somewhat effective
Clostridium
Clostridium
Fatal necrotic enteritis
Several bacteria, especially Clostridium
perfringens type C (also tetanus & botulism)
Young piglets will die within 36 hours; in the
chronic form they may live 1 week
Dehydration; red feces
Antibiotics can be effective
Coccidia
Obligatory intracellular protozoan parasite
Isospora suis
Symptoms start 7-14 days of age; yellow to
grayish diarrhea; rancid odor
Several anticoccidials to piglets (giving to
sows not effective)
Suggest: stringent sanitation; all-in-all-out
Rotavirus
Virus of the Reoviridae family of the genus
Rotavirus
Very common in nature; many serotypes
12-24 h incubation period; nursing pigs most
affected; can be high mortality or a mild
scours; weanlings may show signs
Expose sows to give piglets immunity
Others
Reproductive
Parasites
Porcine Stress Syndrome
Prolapse, Ulcer & Hernia
Mycotoxins
Skin/joint problems, esp. Erysipelas
MMA
Behavioral problems
Reproductive
Brucellosis (see above)
Leptospirosis
Parvo Virus
PRRS (see above)
Leptospirosis
Bacteria of the Leptospira; gram
negative rods; 7 serotypes (or more)
Infection of mucous membranes
Mild symptoms of anorexia, listlessness
Major reproductive problems: abortions,
lower farrowing rates
Vaccines are available
Parvo Virus
Virus of family Parvoviridae; DNA
Embryonic and fetal deaths
Main symptom is stillborn pigs or lower
numbers born alive
Vaccines are available
Parasites
No excuse to have them
Trichinosis
Ascarid
Kidney
Mange
Lice
Ascarid life
cycle
Trichina
Porcine Stress Syndrome
Porcine Stress Syndrome
Genetic condition caused by a mutation
of a gene
Malignant hyperthermia
Halothane gene Hal 1873; genetic test
Single gene: carrier, mono-mutants
Two genes; di-mutant
Test and eliminate
Prolapse, Ulcer & Hernia
Genetic predisposition to each
Prolapses can be rectal or vaginal
Hernias can be inguinal or scrotal
Multi-factorial causes
Diet contributes to all, but not the main
cause
Prolapse, Ulcer & Hernia
Mycotoxins
Metabolites of mold/fungal growth from
the genus Fusarium
Aflotoxins, Ochratoxin and citrinin,
Trichothecenes, Zeralenone, Ergot and
Fumonisins
Reduce feed intake and several cause
reproductive problems due to steroid
activity
MMA
Mastitis, Metritis, Agalagtia (usually
hypogalactia)
Multi-factorial cause; genetic
predisposition; bacterial infections;
constipation; lack of exercise
Piglets waste away and die due to
malnutrition
Skin/joint problems, esp.
Erysipelas
Erysipelas, diamond skin disease,
caused by a bacteria Erysipelothrix
rhusiopathiae; fever, followed by skin
lesions, and then joint inflammation
Vaccines available for Erysipelas
Other bacteria can cause skin and/or
joint inflammation: Streptococci,
Staphylococci
Behavioral Problems
Tail biting & ear chewing
Savaging piglets
Naval/Urine sucking
Not a problem:
-- bar biting
-- phantom nest building
-- aggression in pigs less than 100 lb
Behavioral Problems
PMWS and PDNS pictures
PMWS
PDNS
The End
Thanks to Iowa State University for
swine disease pictures. See:
http://www.vetmed.iastate.edu/departme
nts/vdpam/swine/diseases/byfarmarea/
nurseryandfinishing/