Severe signs: conjunctivitis, obtundation, anorexia, V, D, severe dehydration, death.
Neurologic signs: may be delayed up to 6 weeks. Myoclonus, old dog encephalitis (after recovery from mild/inapparent infection)
What is an important differential for distemper?
What are the characteristics of distemper virus?
enveloped RNA virus
What is the main source of distemper virus, and when are infections seen?
Most infections subclinical
See at weaning in dogs and cats (vaccinated population)
Shed in resp secretions, feces and urine for 1-3 months
What is the pathogenesis of distemper infection?
Lymphoid tissue: inhaled virus infects URT epi -> replication in macrophages while spreading through lymphatics -> infects tonsils and bronchial nodes -> infects systemic lymhoid tissue in GIT, spleen, MLN, kupffer cells on days 2-6 -> fever and lymphopenia
Epi and nervous tissue: hematogenous spread from lymphoid tissue to epi and CNS tissue on days 8-9 -> viral shedding and good-intermediate-poor humoral or response -> virus elimination or persistent -infection-fulminant epi infection -> no CS or CNS / cuteanous / ocular CS or severe GI signs / pneumonia / +- CNS signs
What is the px of distemper infection?
CNS signs = poor prognosis, could develop at any time
How is distemper infection dx?
CBC with lymphopenia, neutrophilic leukocytosis, distemper inclusions
Thoracic rads for intersitial coalescing to alveolar pattern
Serology IgG compared to CSF (differentiate from vaccinated with C coefficient)
Conjuctival scrapings to apply IFA to look for inclusions
What is the tx for distemper infection?
Treatment is purely supportive
Nebulization and coupage
Neurologic signs are usually permanent, and may occur later
How is distemper infection prevented?
Vaccinate q3-4 weeks from 6-16 weeks (need two doses in pups > 8-10 weeks)
Booster at 1 year (then every 3 years)
All are MLV except one recombinant
What is infectious canine hepatitis caused by, and what animals does it affect?
Usually young puppies
Preferentially targets endothelial cells and hepatocytes
Caused by canine adenovirus 1 (non-enveloped DNA virus)
Probably now extinct in the US
What is the pathophysiology of ICH infection?
infects local LN = viremia 4-8 days
systemic spread allows viral shedding in all secretions
good, partial or poor ab response
recovery with minimal endothelial damage (good), chronic hepatitis (partial), severe hepatic centrilobular necrosis and DIC (poor)
all cases have persistent renal tubular infection and shed virus in the urine from day 14 to 6-9 months
What are the CS of ICH infection?
Most infections are subclinical
Acute form is usually 6-10 weeks, or older unvaccinated dogs that show fever, anorexia, depression, TONSILLITIS, hepatomegaly, edema, ascites, C, V, D, hemorrhage
uveitis and corneal edema (direct viral damage and type 3 hypersensitivity that resolves in 1-2 weeks)
glomerular injury (direct viral damage and Ab-Ag complex deposition)