Swine Viral Diseases Flashcards
Porcine circovirus 1
Not highly prevalent in pigs (apathogenic)
Porcine circovirus 2
Porcine circovirus associated dz affects weanling pigs @ 7-15w and occasionally in adults
Resp. dz (lung)- mostly subclin/ mild
_______ is a novel emerging virus
PC3
What can PC2 be associated with?
Postweaning multisystemic wasting syndrome (PMWS)
Porcine dermatitis and nephropathy syndrome (PDNS)
Porcine resp. dz complex (PRDC)- most common with PRRSV and swine influenza
Granulomatous enteritis
Exudative epidermis
Necrotizing lymphadenitis
leads to mortality rate up to 50%
Pathogenesis of PC2
Lymphos, epithelial and endothelial cells → lympho depletion, alteration of monos and macro function and petechial hemorrhage
What enhances PC2?
Predispotion to secondary microbial infections: parvo, M. hyopneumoniae, PRRS virus and swine influenza
Postweaning multisystemic wasting syndrome (PMWS)
Affects all organs
Coalescing foci of granulomatous inflamm. in lung
Botryoid IBs
Porcine dermatitis and nephropathy syndrome (PDNS)
Ischemic necrosis of skin (rear legs)
Vasculitis and glomerulonephritis of kidney
Porcine resp. disease
Late-term abortion, stillborn fetuses exhibit fibrosisng and necrotizing myocarditis
PC2 transmission
Direct contact, semen, fomites and biting insects
Found in blood, saliva, feces, urine and semen of infected
Dx of PC2
Wasting, lesions and presence of Ag or DNA
IHC (# and distribution of virus-infected cells)
Quantitative PCR (viral load)
DD of PC2
PRRS (wasting in PC, repro in both)
Parvo (herpes, repro and neuro)
African Swine (cutaneous, hemorr. in skin, kidney petechial, neuro, foreign)
Vaccines of PC2
Chimeric recombinant of PC1 (genetic backbone) and PC2 (capsid protein)
Orthomyxoviridae causes _______________
Swine influenza viruses
genus: influenza v. A
How are pigs important for influenza?
Mixing vessel due to susceptibility to avian and human influenza (receptors to both)
emerging due to H and N proteins
CS of swine influenza virus
Fever, apathy, impotence and resp. distress
Quick recovery (3-6d), death 1% from bronchopneumonia in stressed animals
Swine influenza epidemiology
Mostly in late fall/ winter
Trasmission of Swine influenza
Entry via aerosols
Replicates in epithelium of nasal cavity and large airways
Lesions associated with Swine influenza
Bronchointerstitial pneumonia, demarcated lung lesion in apical and cardia
Hyperemia and inflamm. exudate
Histology of Swine influenza
Epithelial surfaces denuded, intraluminal debris in airways, collapsed airways, emphysema
DD of swine infleunza
Actinobacillus pleuropneumoniae (hemorr. lungs, high mortality)
Mycoplasma hyopneumoniae
M. hemolytica
Dx of Swine influenza
Cell cx (virus isolation → MDCK cells, eggs)
RT-PCR (primers of H and N sequence)
IF, IHC
Serology: HAI and ELISA in unvx swine
Immunity and prevention of Swine influenza
All- in all out
Vx: killed with H1N2 and H3N2 subtypes
Arteriviridae causes __________
Porcine R & R syndrome virus
Porcine R & R syndrome virus
Infects domestic and wild pigs
Genotypes 1 (europe) and 2 (NA)
Two phases: repro failure and postweaning resp. dz
CS of PRRSV
Post-weaning: cyanosis of extremities and pneumonia
Nursery pigs: roughened hair coats and reduced growth rate
Reproductive failure with PRRSV
Late stage (after 90d)
Piglets born after in utero infection: weak and immunocompromised
Abortion, stillbirth, mummies, premature
Transmission of PRRSV
Direct contact (pugilism)
Transplacental
Aerosol
Shed in all secretion and excretions
Pathology of PRRSV
Replicates in macros in the lung and lymphoid tissue
LN enlargement and interstitial pneumonia
Dx of PRRSV
CS and lesions
RT-PCR, ICH, ELISA, cell cx in lung, macros, african green monkey cell and cotton rat lung cells
DD of PRRSV
Parvo, pseudorabies, circovirus causing repro. failure
Pleuropneumonia, streptococcus suis and infleunza causing resp. problems
Immunity and control of PRRSV
Exclusion in free herds (herd closure)
Vx and management for enzootic infection: commercial, modified-live vx
What are the most common pathogens causing reproductive failure in swine?
Porcine pravo
Suid HV1 (pseudorabies or aujeszky’s)
Classical swine fever (hog cholera)
Porcine circovirus 2
Porcine parvovirus
Reproductive failure (rarely abortion)- preg gilts and sows
Associated with resp. dz, vesicular dz of feet and mouth in young pigs
Pathogenesis of swine parvo
Infects the fetus
Replicated in lymphos, monos and macros causing failure to mount an immune response
Transmission of swine parvo
Oronasal- contaminated floor by secretions and excretions