Infections of the pig
Viral infections of the respiratory
tract
 PRRS
 Cirkovirus
(PCV2)
 Aujeszky disease - Pseudorabies
 Inclusion rhinitis
 Swine influenza
Porcine Reproductive and
Respiratory disease syndrome
virus
Affinitou to respiratory ang genital system
 Antigennic variability, european and
american genotypes
 Strains differ in virulence

Pathogenesis
Infection by inhalation–aerosol
 Alveolar macrophage are target cells for
primary replication
 Respiratory signs are apparent in piglets
older than 3 weeks
 Antibodies can enhance virus infection

Pathological changes


Periocullar oedema, conjunctivitis, blue
coloration of eyes, vulva and snout
Interstitial pneumonia, loss of cilliar epithelial
cells
Porcine Circovirus 2
 PMWS
(Postweaning Multisystemic
Wasting Syndrome)
Clinical signs
Affected age category 5 – 12 weeks
 Respiratory signs
 Growth retardation
 Enlargement of lymph nodes
 Anemia, icterus
 Fever
PMWS (Postweaning Multisystemic Wasting
Syndrome)
PDNS (Porcine Dermatitis and Nephropathy
Syndrome)
Pathogenesis is still unclear !!
PPV
PRRS
PCV-2
Virus genotype?
Stress
PMWS
Immunosupression
Immunostimulation
PCV-2 + immunomodulation =
PMWS
Immunosupression in PCV2 infection
Lymphoid depletion
 Loss of lymphatic follicles
 Atrophy of lymphatic organs
 Loss of circulating B and T lymphocytes

Secondary infection
 Doesn´t produce antibodies
 Doesn´t respond to vaccination

PRDC – PCV2
 Porcine
respiratory disease complex
syndrome
 Multiethiological
 Age category 16 or more weeks
 Virus is in the lung tissue, no PA
changes in lymphonodes
Swine influenza
 Acute,
febrile disease
 Cough, fever, ocullar and nasal
discharge
 Very short incubation period
 Colostral antibodies doesn´t protect
agains disease
Aujeszky diseasePseudorabies
 Pig
is the primary host and the
reservoior for the virus
 Respiratory transmission
 Incubation period 2-3 days
 Primary replication in oropharynx
 Latency in g. trigeminale
Aujeszky diseasePseudorabies
 Fever,
anorexia, vomiting, ataxia,
respiratory signs
 Pneumonia
 Necrotizing tonsilitis
 Keratoconjunktivitis
Bacterial infections in the
respiratory system
The upper respiratory tract I.
 Non
progresive rhinitis atrophicans
(bordetelosis)
– Bordetella bronchiseptica
 progresive
rhinitis atrophicans
(toxinogennic pasteurellosis)
– Pasteurella multocida
 (dermonecrotoxin-
positive strains)
The lower respiratory tract II. pneumonia

enzootic pneumonia
– Mycoplasma hyopneumoniae
– M.hyorhinis

(acute pasteurellosis)
– P. multocida type A, D,.
– Bordetella bronchiseptica
 (piglets
older than 3 or 4 days)
– Arcanobacterium pyogenes
– Streptococcus suis (serovars 2,1, 7)
The lower respiratory tract III.
 Pleuropneumonia
(peracute or acute)
– A.pleuropneumoniae (serovars 7,9,11)
 chronic
pleuropneumonia
– A.pleuropneumoniae (serovar 2)
 Pleuritis
– Haemophilus parasuis
Viral diseases of the urogenital
system
 Porcine
Parvovirus
 PRRS
 Pseudorabies
 Porcine
Circovirus 2
 La piedad virus
PRRS
 Abortions,
premature delivery, weak
piglets, agalactia
 Late pregnancy
 Virus is disseminated by infected
macrophages
 Placenta is not permeabile till the ½
of the pregnancy
 No macroscopic changes on aborted
piglets
Pathogenesis
 Incubation
 Maximal
period 7 – 10 days
virus shedding 3. – 13. days
p.i.
 Length
of shedding 10 – 35 days,
urine, feces, semen, nasal secretions
Circovirus diseases
 Virus
is present in the semen of
boars
 Transplacental infection
– Abortions
– Mumification
– Dead piglets
Affected age categories

Piglets

Sows

–
–
–
–

PMWS
PDNS
PRDC
Secondary infection
Piglets
– Pneumonia
– PRDC
– Secondary infection
– Reproductive signs
Sows
– Reproductive signs

Boars
Virus shedding



Respiratory route
Contact
Orofecal transmission


Respiratory route
Contact

Transplacental
infection

Transplacental
infection

Shedding in the
semen

Shedding in the
semen
Diagnostics
Virus quantification
 Detection of
antobodies sensless



Virus detection (RTPCR)
Detection of
antibodies
Porcine Parvovirus

Enzootic

Infection by oronasal route, shedding in feces last
for at least 14 days

Viremia – transplacental infection

abortions, mumification

Only one piglets from the litter can be affected

Infection in adult animals in inapparent
Aujeszkyho disease Pseudorabies
 Abortions
in sows, stillbirth or
mumification
 Infection is followed by infections in
10 days
 Periorchitis in boars
Porcine Enterovirus
 SMEDI
syndrome
THE URINARY SYSTEM
 cystitis
– E.coli
 cyto-pyelonephritis
– Actinobaculum suis
– E.coli
THE REPRODUCTIVE
SYSTEM

abortions
– Leptospira icterohaemorrhagiae
– Haemophilus parasuis

endometritis/metritis
– co-infection with G- bacteria
– E.coli, Pasteurella spp.,
Viral infections of enteric tract
 Transmissible
gastroenteritis virus
 Swine Rotavirus
 Classical swine fever virus
 Vesicular stomatitis virus
Transmissible gastroenteritis virus
Enzootic disease
 Coronavirus with tropism to mature
enterocytes
 Oral infection
 Sudden onset, incubation period 2-3 days
 Malabsorption syndrome, watery diarrhoea
 High mortality (2-3 days p.i.) decrease
with age (till 14 days - almost 100%)

Transmissible gastroenteritis virus
 Systemic
antibodies doesn´t protect
 Lactogennic immunity (IgA) is
necessary
Porcine Rotavirus
 Ubikvitous
virus
 Host specificity, cross reactivity
 Critical period:


1 – 3 weeks
2-7 days post weaning
 White,
yellow watery diarrhoea
 Pathogenesis is similar to TGE
Bacterial infections in
THE ALIMENTARY TRACT
THE ALIMENTARY TRACT I.
 necrotic
stomatitis
– Fusobacterium necroforum,
– Staphylococcus aureus
 gastritis
– Helicobacter suis ??
THE ALIMENTARY TRACT II.


Enteritis /enterotoxicosis/enterotoxemia/
colibacillosis:
– neonatal diarrhoea, E.coli : F4, F5, F6, ST, LT positive
– E.coli (ETEC,ETEEC) postweaning diarrhoea: E. coli F18,
F4



Oedema diseases, E. coli : VT positive (VTEC)
isolates
necrotic enteritis in piglets C. perfringens type A
, cpb2+
Haemorrhagic enetritis
– C. perfringens typ C
– Salmonella Typhimurium
– Salmonella Choleraesuis
THE ALIMENTARY TARCT III.
– Bacillus cereus, enterotoxines positive strains (ET+).

proliferative enteropathy ("ileitis")
– Lawsonia intracellularis

swine dysentery
– Brachyspira hyodysenteriae

colonic spirochaetosis
– Brachyspira pilosicoli

polyserositis and peritonitis
– H.parasuis
– M.hyopneumoniae
Viral infections of CNS
 Pseudorabies
 Porcine
Enterovirus (Teschovirus)
 Nipah virus
THE CENTRAL NERVOUS
SYSTEM
 meningo-encephalitis
– Streptococcus suis type 2
– Haemophilus parasuis
– Salmonella Choleraesuis
– Listeria monocytogenes
Porcine Teschovirus
Picornavirus
 Polioencephalomyelitis, frequent
inapparent infections
 Highly virulen strains are causing
(serotype 1) Teschen disease with high
mortality
 Replication in the gut and mononuclear
cells of Lamina propria, hematogenous
spread to CNS
 Fever, ataxia, convulsions, paralysis

Pseudorabies
 In
piglets only
 Depression, ataxia, tremor,
convulsion, pruritus
 Nonpurulent meningoencephalitis
and ganglioneuritis
THE BLOOD

SEPTICEMIA
–
–
–
–
–
–
–
–

Salmonella Choleraesuis
E.rhusiopathiae
Streptococcus suis type 1,2
S. equi subsp. equisimilis, S. porcinus
Actinobacillus suis,
A.pleuropneumoniae,
H.parasuis
E.coli
endocarditis
– Streptococcus suis ,
– A.pleuropneumoniae
– E.rhusiopathiae
THE MUSCULOSKELETAL
SYSTEM

artritis-polyartritis
–
–
–
–
–
–
–
Streptococcus suis, type 1
S.dysgalactiae,
H.parasuis
Mycoplasma hyosinoviae,
M.hyorhinis
Actinobacillus suis
Arcanobacterium pyogenes, E.rhusiopathiae
Virus infections of the skin
 Porcine
Circovirus 2
 Porcine poxvirus
 Foot and mouth disease virus
 Vesicular exanthema virus
 Porcine Vesicular disease
THE SKIN

Exudative epidermitis
– Staphylococcus hyicus

Pustular dermatitis
– Staphylococcus aureus

Erysipelas
– E. rhusiopathiae

absceses
– Actinomyces pyogenes,
– S.porcinus, F.necroforum