Canine Parvovirus

Antigenicity

• 2 Canine Viruses:
  • Canine Parvovirus 1 (CPV1): avirulent, ubiquitous in canine population
  • Canine Parvovirus 2 (CPV2): new virus emerged in the late 1970's
• Antigenic variants occur

Hosts

• Dogs
• CPV 2a/2b can cause disease in cats

Pathogenesis

• Oropharyngeal infection followed by viremia
• 2 distinct syndromes:

1. Myocarditis in puppies aged 3-8 weeks
   • Virus targets rapidly dividing myocardium
   • Sudden death, fading puppy syndrome
   • Now rare due to widespread passive immunity
2. Enteritis in puppies >8 weeks of age
   • Virus targets intestinal crypts
   • Villi shorten, then destruction of cypt cells
   • Gray, persistent, foul-smelling diarrhoea or hemorrhagic enteritis
   • High morbidity, low mortality (10%)

Epidemiology

• Orofecal transmission
• Host range is controlled by only a few amino acids

Diagnosis

• HA or ELISA for virus

Control

• Vaccination, usually in combination with distemper and hepatitis. With first vaccination at 8-10 weeks and the second vaccination two weeks after the first, 10-12 weeks.
• Thorough disinfection after disease

Parvovirus Enteritis

Canine Disease

• Until 1978 Parvovirus enteriris was totally unknown in dogs.
• First seen in dogs in Australia.
  • Apeared very similar but perhaps slightly worse than the disease seen in the cat.
  • A new and distinct disease, but the virus is very closely related to the feline virus.
    • Viral DNA is 98% homologous to the feline virus.
  • The canine virus does NOT cause disease in cats.
• Clinical
  • Causes enteritis in young dogs over 6 weeks old.
  • Causes myocarditis in puppies.
  • Mainly affects the small intestine.
• Vaccines are very effective, but the virus is hardy and survives in the environment.
• Diagnosis:
  • Look for viral antigen in the faeces by the red cell agglutination test.
  • Immunoflurescence.
  • ELISA.
  • Serology.