canine viral diseases 2 - Tesse Flashcards
Distemper is part of what family
Paramyxoviridae
What are the main species that canine distemper affects?
Canidae and large Felidae
what is the classification of Distemper
ssRNA (-)
How long can distemper stay in the animals body
60 days
what types of animal materials contain CDV
respiratory and ocular fluids and other exudates (urine, feces, skin)
What determines the severity of clinical illness with CDV
antibody response
If an animal has inadequate host immunity, what part of the body will be invaded (Distemper)
all epithelial tissues and CNS
t/f adequate host immunity will prevent the virus from entering the CNS (distemper)
false. it may still enter the CNS, but the prevalence of CNS signs is lower
what are acute signs of CDV
conjunctivitis
fever
anorexia
vomiting
diarrhea
what are chronic signs of CDV
ataxia
tremors
myoclonus
seizures
moribund -> death
what is the pathogenesis of CNS clinical signs of CDV
aerosol -> replication in oral pharynx -> cells associated viremia in lymphocytes -> CNS -> demyelinating encephalitis, axonal injury, plasmacytic/lymphocytic infiltrates.
Results: seizures, myoclonus, old dog encephalitis, hard pad disease, death
what is the prevalence of neurological disease in CDV
30% of canines and almost all wild carnivores
what percentage of CDV infections in domestic dogs are subclinical
50-70%
what causes the biphasic fever that occurs at 3-4 days and then 14 days in dogs with CDV
lymphocytic viremia
what is enamel hypoplasia
direct viral infection and destruction of ameloblasts that produce enamel by CDV . occurs in dogs <6 mo of age
what is hard pad disease
hyperkeratosis of foot pads caused by CDV. this is due to CDV’s tropism for epithelial cells, their persistnece in and proliferation of keratinocytes
What histological findings are present once CDV is disseminated by the CSF
perivascular cuffing, inclusion bodies (mainly intracytoplasmic) and demyelination
some examples of CDV presentation in wildlife
suppurative conjunctivitis, syncytia/intracytoplasmic inclusions in the conjunctiva, and the brain
how is CDV diagnosed
molecular assays, serological assays, virus isolation and neutralization assay, pathological examination
what types of vaccines are available for CDV
attenuated and modified virus vx, recombinant canarypox vectored vx, inactivated vaccine
what are pros of attenuated and modified CDV vx
long lasting
what are cons of attenuated and modified CDV vx
reversion to virulent virus possible
not for immunosuppressed and pregnant dogs, or non-canine species
can be fatal to european minks and ferrets
what are pros of canarypox vx for CDV
licensed for ferrets, use for zoo and park suseptible animals recommended
what are cons of canarypox vx for CDV
does not prevent infection, but protects against CD
what are characteristics of inactivated vx for CDV
does not prevent infection but protects against CD
what species are resistant to rabies
birds, reptiles, amphibians
what is the classifcation of rabies
- ss RNA, enveloped
What mammals are susceptible to rabies
all of them
What family does rabies belong to
rhabdoviridae
where is the only place on earth free of rabies
New Zealand
what are the reservoirs of rabies in canada
fox, bats, skunks and raccoons
what are the main reservoirs of rabies in alberta
bats followed by skunks and then cats.
what are the main reservoirs of rabies in ontario
foxes raccoons and other animals
describe the Rabies transmission cycle
canine and wildlife reservoirs can spill into non-reservoir livestock or non-reservoir domestic animals, which can all lead to interactions with the human population (and therefore cause death)
what is reservoir transmission of rabies to humans
direct transmission from either a canine member or a wildlife member to a human
what is a non-reservoir transmission of rabies to humans
indirect transmission from one of the reservoirs (wildlife or canine) to humans through a non-reservoir (livestock, domestic animals)
what is the mode of transmission of rabies
saliva, cerebrospinal fluid, and infected neural tissues via cuts in skin, bite wounds, mucous membranes, or aerosols
what is the incubation period of rabies
days-months
how fast can rabies be transported via anterograde transport
100 mm per day
what is the fatality rate of rabies
100%
what species get the paralytic form of rabies
horses, cattle, bats, and dogs
what species get the furious form of rabies
cats, dogs
what are the histological signs of rabies
non-suppurative encephalomyelitis
ganglioneuritis (babes nodules)
intracytoplasmic inclusion bodies
how is rabies diagnosed
if rabies is suspected, animal should be quarantined/euthanized, and the head removed for lab shipment on ice. Rabies diagnosis is done by the CFIA. Fresh brain tissue is stained with antibodies, and will be fluorescent if positive.
what vx are there for rabies
modified-live, recombinant, and inactivated.
vaccinia-rabies glycoprotein recombinant virus vaccine uses ____ virus as a vector
pox
what two specific ORAL rabies vx should you know that are available for wildlife?
vaccinia-rabies glycoprotein recombinant virus
adenovirus type 5 vector, expressing rabies virus glycoprotein
what are the WHO guidelines for rabies control
dog movement control and quarantine
mass immunization
stray dog control and registration
notification of suspected cases
how many dogs would need to be vaccinated for rabies for herd immunity to occur?
70%
what are core vaccines
vaccines for diseases that are widespread, cause serious illness, and/or highly contagious
what are the core vaccines in dogs
canine distemper
infectious canine hepatitis
canine parvo
rabies
what are non-core vaccines
vaccines for diseases that pose particular risk to an individual dog
what are the non-core vaccines for dogs
bordetellosis
canine parainfluenza
leptospirosis
borreliosis
coronavirus
what are the two distinct forms of canine parvovirus (CPV)
CPV-2: pathogenic
CPV-1/minute virus: nonpathogenic
what determines the host range in CPV?
amino acid sequences of the viral capsid
who is most susceptible to CPV
canids, young unvaccinated puppies, some breeds (doberman, rottweiler, staffies, german shepards), concurrent helminthic, protozoal, and bacterial infections
how is CPV transmitted
contact with contaminated feces -> fecal oral route
indirectly with fomites
How does manifestation of parvovirus differ between canines and porcines
canine: lymphopenia, enteritis, neonatal myocarditis
Porcine: reproductive (stillbirth, abortion, fetal death, mummification, infertility)
What is the pathogenesis of CPV in utero
fetus -> myocarditis to either sudden death or congestive heart failure causing death after the puppy is born
what is the pathogenesis of CPV in neonates
what is the pathogenesis of CPV postnatally
t/f: severity of CPV is not dose related
false. many older dogs or pups that receive low viral doses will be asymptomatic since the infection is highly dose related
what are clinical signs associated with CPV
diarrhea, dehydration and profound weight loss
hemorrhagic intestinal serosal surface
t/f: unlike most other DNA viruses, parvoviruses are unable to switch on DNA syntehsis in host cells. THus, in order for viral replication to occur, the infected cells must be actively dividing
true
why does CPV lead to crypt necrosis
parvoviruses need to replicate in cells that actively divide. Therefore they target crypt cells and cause necrosis
how is CPV diagnosed
foul smelling, bloody diarrhea in pups
Electromicroscopy of fecal material
immunochromatography
PCR
how is CPV prevented
vaccination (can be multivalent with distemper, adenovirus, lepto, rabies)
what level of titer is required to be protected against CPV
> 1:40
the maternal antibody for CPV has a half life of:
9-10 days
when should you vaccinate for CPV
from 9 weeks to 16-20 weeks, 2-3 weeks apart.
When is the window of susceptibility for CPV
ages 9-12 weeks, because maternal antibodies have dropped below a level needed for protection, and the puppies own antibodies have not yet reached the level needed for protection
what type of virus is a canine coronavirus (CCoV)
+ ssRNA, enveloped
what are the clinical signs of pantropic CCoV
fever, lethargy, hemorrhagic diarrhea, severe lymphopenia, neurological signs
transmission of enteric CCoV
highly contagious. incubation period is 1-3 days. infected dogs shed for 6-9 days, but can shed up to 6 months. Fecal oral.
what is the pathogenesis of enteric CCoV
targets mature enterocytes on the villi of the intestine. the tip epithelium is replaced by non-functional low columnar to cuboidal epithelium, rendering them nonfunctional.
leads to fusion of villi, villus atrophy and deepening of the crypts
t/f: CPV susceptibility increased with enteric CCoV infection
true
what are the several co-circulating genotypes of canine distemper based on
H - gene variation
if host immunity is inadequate (poor antibody response), what will happen to a dog with canine distemper viremia?
widespread invasion of all epithelial tissues and CNS. This can either lead to a severe or mild systemic response, depending on the extent of the antibody response. regardess, if the animal survives, it will show CNS signs.
if host immunity is adequate (good antibody response) and a dog is infected with canine distemper, what will happen?
virus may enter the CNS, but the good antibody response will result in a low chance of CNS signs.
