Lecture 4: Parvo viruses and circoviruses Flashcards
(33 cards)
clinical signs of porcine parvovirus
usually seen in gilts that are not immune and bred to new boar
- no clinical disease in non-pregnant sows
- abortion uncommon
sow may be rebred without trouble bc they are immune after infection!
general characteristics of parvoviruses and circoviruses
- small icosahedral virion with linear ssDNA
- eosinophilic intranuclear inclusions!!
- naked: therefore environmentally resistant**
- replicate in nucleus of rapidly dividing cells**
- –> GI tract = diarrhea
- –> WBC = panleukopenia
- –> pregnancy = SMEDI (stillbirth, mummification, ED = embryonic death, Infertility)
transmission of parvo virus in pigs
- found in boar semen, testicles and feces - can be shed continouously
- virus can survive for 135 days in swine pens
dx of parvovirus in pigs
mummified fetus - best sample for IF/PCR
serology if no fetus available
prevention of parvovirus in pigs
- vaccination 3 - 4 weeks prior to breeding
- vaccinate when maternal antibodies drop bc they can interfere with immune response
feline panleukopenia virus general characteristics
caused by parvo virus
- highly contagious
- often fatal (more severe in kittens)
transmission of feline panleukopenia virus
direct: feces, urine, saliva, vomit of infected cats
indirect: contaminated fomites of fleas
vertical transmission
virus shed in urine and feces up to 6 weeks after recovery
clinical signs of feline panleukopenia virus
peracute disease > 104 = death
if cat survives: lethary, anorexia, vomiting of yellow fluid, early fever followed by hypothermia
GIT: palpably swollen and filled with gas/liquid
- most significant aspect is that since GI has been compromised, animal can no longer take in any fluid or nutrients. so hydration is most important
clinical signs of in uteruo infection of feline panleukopenia virus
cerebellar hypoplasia - loss of balance, broad-based stance, ataxia tremor,etc
stunted growth
diagnosis of feline panleukopenia virus
clinical signs
CBC/chemistry (profound leukopenia, hypoalbuminemia)
canine ELISA for CPV-2
PCR
tx and prevention of feline panleukopenia virus
tx: supportive + antibiotics
prevention: vaccination, disinfection of environment
canine parvovirus: disease characteristics
occurs in puppies less than 6 months of age
- panzootic of high morbidity and mortality
- families susceptible to natural infection: canines (includes foxes and coyotes), mustelidae (minks, ferrets), felidae (cats and large cats)
clinical signs: canine parvovirus
severe disease most common in rapidly growing puppies
enteritis syndrome (vomiting and bloody diarrhea)
septic shock due to intestinal villi destruction and translocation of bacteria
myocarditis if puppies are infected in utero (rare)
dx and tx of canine parvovirus
- clinical signs and smell!
- CBC/chem: hypoalbunemia, neutropenia
- ELISA snap test - CPV-2 in feces
tx: fluids, abx, antiemetics, esophagitis therapy (H2 receptor antagonists for vomiting)
prevention of canine parvovirus-2
vaccination: maternal antibodies will interfere with vaccination
disinfection (bleach)
reduce exposure
Circoviruses - general stuff (architecture, shape, which species it infects, replication process)
- smallest known DNA virus of vertebrates
- naked, icosahedral shape
- circular, ssDNA
- pathogens of bird and swine
- replication occurs in cell nucleus of rapidly dividing cells. virus produces large basophilic intracytoplasmic and occasionally intranuclear inclusion bodies
- persistent infection is common
what virus causes post-weaning polysystemic wasting syndrome?
porcine circavirus-2
post-weaning polysystemic wasting syndrome: general characteristics
- effects immune system targeting macrophages and lymphocytes
- causes granulomatous infalmmation in lymph tissue, lungs, liver and heart intestine
- macrophages show large “botryoid” basophilic intracytoplasmic inclusion bodies
- lymphocyte depletion and reticuloendothelial cell hyperplasia
clinical signs of porcine circovirus-2
emaciation, hemmorhagic epidermitis associated with necrotic vasculitis and arteritis, respiratory disease
diagnosis of porcine circovirus-2: postweaning polysystemic wasting syndrome
- quantitation of viral load by qPCR in lymphoid cells is important
- IHC/IF of infected tissues
management of postweaning polysystemic wasting syndrome
- only use semen from clean boars
- practice all-in/all-out system
- ensure piglets get lots of colostrum
- dont use equipment between litters without disinfection
environment and control for postweaning polysystemic wasting syndrome
environment: appropriate temp/humidity, consider other vaccination that reduce coinfections (ie parvo)
control: vaccine - inactivated subunits
what virus causes psittacine beak and feather disease?
circovirus
general characteristics of psittacine beak and feather disease
- debilitating progrssive disease of cockatoos, parrots, budgerigars
- targets the feather follicles, beak and claws (growing cells) –> necrosis and feather malformation
