Treating canine parvovirus and its prognosis

Canine parvovirus. What is it?

Parvovirus is transmitted orally and resistant in the environment. It has an incubation period of approximately 5 days. The virus mainly affects young dogs aged 6 weeks and older, as this is when they lose their maternal immunity. This also means that canine parvovirus is rare among adult dogs because they achieved immunity either via vaccination or subclinical infections.

Treating canine parvovirus: clinical signs

Canine parvovirus courses with acute onset gastroenteritis, anorexia, depression and vomiting, followed by severe haemorrhagic diarrhoea, dehydration, fever and hypothermia. Severe cases may include jaundice and disseminated intravascular coagulation (DIC), accompanied by endotoxic and/or hypovolaemic shock. In most cases there is marked leukopaenia (500–2,000 leukocytes/µL) and normal or reduced haematocrit levels. Air often accumulates in the intestine as a result of paralytic ileus, which can be confused with a physical intestinal obstruction.

HOW SHOULD IT BE TREATED?

Any approach must prevent dehydration and complications such as shock and include the use of antibiotics. Here is a brief explanation of the indicated treatment:

• Fluid therapy: use Ringer’s lactate solution supplemented with KCl, to which dextrose can be added in the event of hypoglycaemia due to sepsis.
• Antibiotic therapy to control sepsis and leukopaenia using amoxicillin and first-generation cephalosporins.
• Use antiemetics such as metoclopramide in continuous rate infusion or bolus doses and antisecretory H2-receptor antagonists such as cimetidine or ranitidine.
• Use a blood transfusion in the case of severe hypovolaemia or hypoproteinaemia.
• Absolute fasting for 24 h without vomiting or melena. This usually happens in 3–5 days; bland diet in small portions.

The most common complications are sepsis, endotoxaemia and DIC, as indicated above.

Canine parvovirus can be prevented by vaccination. However, it is hard to know the precise moment when it should be administered given the period of susceptibility. In other words, there is a critical period of 1 or 2 weeks after the age of 6 weeks in which puppies have sufficient maternal immunity to inactivate vaccines but not enough to protect from infection (for more information about vaccines, check out this post here).

Prognosis for canine parvovirus

By treating canine parvovirus at an early stage and with close monitoring, the prognosis is now excellent for a disease which killed a lot of puppies in the 1980s.