MODULE 10: VIRAL DISEASES OF COMPANION ANIMALS (RABIES, CANINE DISTEMPER, CANINE PARVOVIRUS)

What is the etiologic agent of rabies?

Lyssavirus

What family does rabies virus belong to?

Rhabdoviridae

What are the characteristics of rabies virus?

Enveloped, bullet-shaped, negative-sense single-stranded RNA

What animals serve as hosts for rabies?

Dogs, cats, and wildlife such as bats, raccoons, and foxes

Is rabies zoonotic?

Yes, it is fatal in humans

How is rabies transmitted?

Through bite wounds via saliva and rarely aerosol exposure

How does rabies spread in the body?

Via peripheral nerves to the central nervous system

What is the pathogenesis of rabies?

Replication at bite site, entry into peripheral nerves, retrograde transport to brain, encephalitis, spread to salivary glands

What is a key histologic feature of rabies?

Negri bodies (intracytoplasmic inclusions)

What are the clinical forms of rabies?

Furious rabies and paralytic (dumb) rabies

What are signs of furious rabies?

Aggression, hypersalivation, behavioral changes

What are signs of paralytic rabies?

Progressive paralysis, dysphagia, death due to respiratory failure

How is rabies diagnosed?

Direct fluorescent antibody test on brain tissue, PCR, histopathology

What is the gold standard test for rabies?

Direct fluorescent antibody test on brain tissue

How is rabies prevented and controlled?

Mandatory vaccination, stray animal control, post-exposure prophylaxis, quarantine laws

What is the etiologic agent of canine distemper?

Canine distemper virus (CDV)

What family does CDV belong to?

Paramyxoviridae

What genus does CDV belong to?

Morbillivirus

What are characteristics of CDV?

Enveloped, negative-sense RNA, related to measles

How is canine distemper transmitted?

Aerosol droplets and direct contact

What is a key feature of distemper pathogenesis?

Immunosuppression

What is the pathogenesis of canine distemper?

Replication in respiratory lymphoid tissue, viremia, systemic spread to respiratory, gastrointestinal, skin, and CNS

What are clinical signs of canine distemper?

Respiratory signs, nasal discharge, pneumonia, vomiting, diarrhea, seizures, myoclonus, paralysis, hyperkeratosis of footpads

What is “hard pad disease”?

Hyperkeratosis of footpads seen in canine distemper

How is canine distemper diagnosed?

PCR, antigen detection, serology, and clinical signs

How is canine distemper prevented?

Core vaccination with modified live vaccine and isolation of infected animals

What is the etiologic agent of canine parvovirus?

Canine parvovirus type 2 (CPV-2)

What family does CPV-2 belong to?

Parvoviridae

What genus does CPV-2 belong to?

Protoparvovirus

What are characteristics of CPV-2?

Non-enveloped, single-stranded DNA, highly resistant in the environment

How is canine parvovirus transmitted?

Fecal-oral route and highly contagious with long environmental persistence

What cells are targeted by canine parvovirus?

Rapidly dividing cells including intestinal crypt cells, bone marrow, lymphoid tissue, and myocardium in neonates

What are the effects of canine parvovirus infection?

Hemorrhagic enteritis, leukopenia, and sepsis

What are clinical signs of canine parvovirus?

Profuse bloody diarrhea, vomiting, dehydration, depression, sudden death in puppies

What is the prognosis of untreated parvovirus infection?

High mortality

How is canine parvovirus diagnosed?

Fecal antigen ELISA, PCR, and CBC showing leukopenia

How is canine parvovirus prevented?

Core vaccination, strict disinfection with bleach, and isolation protocols

What are key differential diagnoses for neurologic signs in dogs?

Rabies and canine distemper

What disease is associated with bloody diarrhea in dogs?

Canine parvovirus

What disease is associated with hyperkeratosis of footpads?

Canine distemper

What signs suggest rabies?

Aggression and hypersalivation