ID - Canine Viral Infections Flashcards
What family and genus does canine distemper virus belong to?
Paramyxoviridae and Morbillivirus
What species can canine distemper infect?
Dogs primarily but also ferrets, badgers, and lions
What diseases are closely related to canine distemper?
Measles mumps, rinderpest, phocine distemper
What is the pathogenesis of canine distemper?
Oronasal infection.
Multiplies in the lymphoid tissue of the respiratory tract.
Widespread multiplication in lymphoid tissue, bone marrow, and spleen.
Virus spreads to epithelial +/- CNS tissues (entry into CNS tissues depends on the immune response of the host)
Where does the canine distemper virus multiply?
Lymphoid tissue, bone marrow, and spleen
What are the clinical signs of canine distemper?
Subclinical Anorexia, depression, pyrexia Ocular and nasal discharge Coughing Conjunctivitis Vomiting and diarrhoea Hyperkeratosis - nose and feet; hard pad Neurological signs - seen 1-3 weeks after other signs - seizures and myoclonus
How can you diagnose canine distemper?
History and clinical signs.
RT-PCR - smears, blood, urine sediment.
Virus isolations from secretions is difficult.
Antibody or viral antigen in CSF is diagnostic
How can you treat canine distemper?
No antivirals; symptomatic and supportive treatment e.g. fluids, anticonvulsants for seizures.
Careful nursing.
Antibacterial cover for secondary infections
Are there vaccines for canine distemper?
Yes
Modified live
Classically vaccinate when MDA (maternally derived antibodies?) decline to non-detectable levels: approx 8-12 weeks of age
Nowadays higher titred vaccines allow earlier finish vaccination if necessary
What is the difference between canine adenovirus types 1 and 2?
CAV-1 - systemic disease and can also cause upper respiratory tract disease
CAV-2 - respiratory disease
What causes infectious hepatitis in dogs?
Canine Adenovirus type 1
What virus is described by the following?
- very hardy, can survive weeks in the environment
- disease now uncommon due to vaccination
- mainly seen in unvaccinated dogs, or on puppy farms
Canine Adenovirus type 1 or Infectious Hepatitis
What is the pathogenesis of infectious hepatitis?
Oronasal infection.
Viraemia.
Virus spreads to many tissues.
Virus then localises and causes damage in hepatic cells and vascular endothelial cells.
Virus persists in kidneys and can be excreted in urine for 6-9 months
What are the clinical signs of infectious hepatitis?
Often dogs <1 year of age. Pyrexia, depression, lethargy. Hepatomegaly. Reluctance to move, abdominal pain. Petecchial haemorrhages - bleeding from venipuncture sites. Vomiting and diarrhoea (haemorrhagic). Coughing. Corneal oedema and uveitis - during clinical recovery
How can you diagnose infectious hepatitis?
Virus isolation from faecal samples or oropharyngeal swabs.
Serology.
Histopathology of liver tissue at postmortem - cowdry A type intranuclear inclusion bodies