Inf. diseases II - Swine diseases (reproduction, varia) 1/2 Flashcards
Porcine brucellosis is an infectious disease of pigs, caused by Brucella suis, and characterized by
abortions and weak or stillborn piglets.
Causative agent of brucellosis.
bacterium Brucella suis
Gram–, facultatively intracellular
Serovars of Brucella suis.
Five serovars
Biovars 1, 2 and 3 maintained in pigs
- 1 and 3, domesticated pigs and wild or feral pigs
- 2 – mainly wild boar (and European hares)
- 1, 3 and 4 – important human pathogens
- 2 is zoonotic, but reported rarely in humans
Brucella suis survival in environment.
Killed by most commonly available disinfectants.
Survival in meat: very short unless frozen (then years).
Can remain viable for MONTHS in water, aborted fetuses, manure, wool, hay, equipment and clothes.
Can withstand dessication.
Host range of brucellosis.
mainly pigs and humans
but specific biovars affect specific other mammal species. occasionally in cattle, small ruminants, horses, dogs etc.
region in which the following brucellosis biovars are found:
Biovar 2
Biovars 1 and 3
Biovar 2 – Europe
Biovars 1 and 3 – worldwide
Morbidity of brucellosis.
varies with the length of time of B. suis in herd
Abortion rate in domesticated pigs 0-80%
Mortality of brucellosis.
low
Death is rare except in the fetus and newborn.
Transmission of brucellosis.
Excretion: all repro. fluids
Direct contact and Fomites
Ingestion of repro. products.
Route: alimentary
IP: of brucellosis
IP: very variable, 3-120 days (average 14-21 days)
Signs depend on the site of localization
Clinical signs of brucellosis in swine. (5)
repro. failure
abortion
weak or stillborn piglets
In boars: epididymitis, orchitis
Swollen joints and tendon sheaths, lameness and incoordination may occur.
Post mortem signs of brucellosis. (4)
Metritis
Orchitis
Osteomyelitis
Abscesses or other purulent lesions in reproductive and non-reproductive organs.
Suspect brucellosis when:
reproductive failure in sows, orchitis in boars and lameness, arthritis or paralysis occur at the same time in a herd.
Material for diagnosis of brucellosis. (6)
Vaginal swabs
Semen
Blood
Testicles (after castration)
Placenta or aborted/stillborn fetuses
LNs; spleen, liver and reproductive organs
Lab analyses for diagnosis of brucellosis. (4)
Serology
Brucellin allergic skin test
Culture – colonies appear after two days of growth
PCR
Tx of brucellosis.
no Tx!
Prevention & control of brucellosis. (3)
Transmission can be reduced by immediate disposal of birth products, contaminated bedding etc followed by thorough cleaning and disinfection.
in-herd Eradication: depopulation or test and removal methods.
Eradication in general:
Quarantine
Test-and-slaughter
Depopulation
No vaccine available.
Describe Brucellosis in humans.
Humans can catch it from swine, dogs, cattle small ruminants.
Fever and nonspecific flu-like symptoms.
Mortality is low (case fatality <5%).
Which biovars of brucellosis are human pathogens?
Biovars 1,3 and 4 are human pathogens
Porcine parvovirus infection is a contagious disease of swine, caused by Parvovirus, and characterized by
reproductive failure.
Causative agent of swine parvovirus infection.
Genus & family.
Genus Parvovirus,
family Parvoviridae
DNA virus
Resistant in the environment
Host range of PPV.
swine
Ubiquitous among swine throughout the world.
Transmission of PPV.
Excretion: feces, urine, vaginal discharge, sperm, fetal membranes and fluids
Direct contact
Fomites (contaminated feed)
Route: alimentary, respiratory or genital
Pathogenesis of PPV.
Pregnant sows/gilts are susceptible in the first half of pregnancy.
- Fetuses die and are reabsorbed or mummified
- If infected later, the virus does not cross placental barrier and thus does not effect fetuses.
From 70th day of pregnancy, fetuses will develop immunoreaction to virus.
Clinical signs of PPV. (5)
Reproductive failure
Decrease in the number of piglets in litter
Stillbirths
Mummified fetuses
Weak neonates
Post mortem signs of PPV. (2)
Non-specific:
aborted fetuses and weak stunted piglets
Material for diagnosis of PPV. (2)
Blood (from sow)
Aborted fetuses
Lab analyses for diagnosis of PPV. (2)
Serology
Identification of the agent
Tx of PPV.
no specific Tx
Pigs become immune after recovering from infection.
Prevention & control of PPV. (2)
Prevention: buy new animals from only seronegative herds.
Vaccination:
Commonly in combination with Erysipelas
Vaccinating pregnant gilts 4-6 weeks before mating and about 2-3 weeks before mating.
Porcine circoviral disease (PCVD) is a contagious disease of swine, caused by Circovirus, and characterized by (2)
post-weaning multisystemic wasting syndrome, and
dermatitis and nephropathy syndrome.
Causative agent of Porcine circoviral disease (PCVD).
Genus and family.
Genus Circovirus,
family Circoviridae
DNA virus (single strand)
Serotypes of PCVD.
Three serotypes:
PCV1 – considered non-pathogenic
PCV2- pathogenic
PCV3- is super new and unknown.
Survival on porcine cirocvirus in the environment. (3)
Resistant to common disinfectants
Resistant to inactivation even at a low pH
Stable at high temperatures
Host range of PCVD.
swine worldwide
Clinical disease in 6-16 week-olds.
But mostly subclinical disease
Secondary bacterial infections are very common.
Morbidity of PCVD.
Morbidity 5-30%
Mortality of PCVD.
Mortality 70-90%
Herds that vaccinate for M. hyopneumoniae have lower mortality (secondary pathogen).
Transmission of PCVD.
Excretion: nasal, ocular, and bronchial secretions; saliva, urine and feces; semen
Direct contact
Fomites
Route: alimentary
Associated syndromes of PCVD. (2)
Postweaning multisystemic wasting syndrome (PMWS)
Porcine dermatitis and nephropathy syndrome (PDNS)
Clinical signs of Postweaning multisystemic wasting syndrome (PMWS). (7)
wasting away.
Labored breathing (pneumonia)
Diarrhea
Enlarged lymph nodes
Jaundice
High mortality
Abortion and weak-born pigs
Clinical signs of Porcine dermatitis and nephropathy syndrome (PDNS). (3)
Skin and kidney lesions
Arthritis
Prevalence within infected herds is low (<1%)
Post mortem lesions of PCVD - Porcine dermatitis and nephropathy syndrome. (3)
Hemorrhagic and necrotic skin lesions
Kidneys are enlarged, pale, and may have pinpoint hemorrhages on the surface.
Post mortem lesions of PCVD - Postweaning multisystemic wasting syndrome. (5)
Enlarged LNs
White spots on kidney’s cortices
Hepatic atrophy and paleness
Catarrhal enteritis
Mummified or edematous fetuses
Material for diagnosis of PCVD. (3)
Blood
LNs
Kidney
Lab analyses for diagnosis of PCVD. (3)
Virus isolation
Serology (ELISA)
PCR
Tx of PCVD.
no specific Tx
If secondary bacterial infections: ABs
Prevention & control of PCVD. (2)
Good animal husbandry
Vaccination (e.g. Circovac)
