Canine Parvo Virus

Description

Canine parvovirus only emerged during the 1970's as a serious infectious disease which causes acute gastrointestinal disease or heart disease in young dogs. In the most serious cases it can be rapidly fatal.

Cause

The cause of Canine Parvovirus disease is a highly contagious DNA-containing virus of which there are two types CPV-1 and CPV-2 . The virus is transmitted through the mouth or nose from faeces. CPV-2 is responsible for the most serious outbreaks of parvovirus enteritis and it can be passed by out in the faeces of a dog within 3-4 days after infection and before clinical signs are seen.

Breed Occurrence

Canine parvovirus (CPV-2) affects all breeds of domesticated dog, as well as wild dogs (including bush-dogs, coyotes, maned wolves) and the virus may also be transmitted to cats, ferrets and mink. CVP-1 appears to only affect domesticated dogs..

Puppies aged 6weeks-6months in some breeds of dog have been reported to have a higher risk of developing canine parvovirus (CPV-2) disease than others, including :

Alaskan sled dogs
Doberman Pinschers
German Shepherd Dogs
Labrador Retrievers
Rottweilers
Staffordshire Terriers (American)
Signs

Some dogs can be infected with canine parvovirus and show no signs at all or just a mild gastroenteritis. Clinical signs are first seen after an incubation period of about 4-5 days. There are two main organ systems involved in canine parvovirus disease (CVP-2):

Gastrointestinal tract - parvoviral enteritis
Vomiting
Bloody diarrhoea
Rapid dehydration
High fever
Depression
Death
Heart disease - can be seen in pups born to unvaccinated mothers
Heart muscle inflammation (called myocarditis)
Heart failure - listless
Distressed pups - crying, difficulty breathing
Diarrhoea
Death
Canine parvovirus disease due to CVP-1 affects the same organs in young puppies up to 3 weeks of age and causes :

mild diarrhoea
vomiting
difficulty breathing
Death - "fading puppy" syndrome
In adult bitches CPV-1 infection may cause :

fading puppy syndrome in her litters
abortion
foetal abnormalities
Complications
Secondary infections including septicaemia and giardia occur in some patients following recovery from the disease.

Diagnosis

Diagnosis of CPV-2 infection can be made by testing faeces with an ELISA antigen test up to 1 week after clinical signs are seen. After this time the dog is no longer shedding virus in its faeces. NB This test does not detect CPV-1

Diagnosis of both CPV-2 and CPV-1 can be made from histopathological examination of infected tissue samples or faeces for virus particles.

Treatment

There is no specific treatment for canine parvovirus, so puppies should be vaccinated against according to the local veterinary practice's normal protocol - usually at least 2 doses from 6 weeks of age. Some pups have strong immunity from the mother and they need to be vaccinated much later. Protection from a vaccine may only last for up to 15 months, so regular boosters are needed. The vaccine is only effective against CPV-2 and there is no vaccine available against CPV-1.

For clinical cases fluid therapy is essential to reverse dehydration and electrolyte abnormalities. Other drugs may also help such as antibiotics and antiemetic drugs (eg metoclopramide) to prevent vomiting. Puppies should be kept warm and in isolation when being treated. Dietary management is important in the recovery of parvovirus patients because the gastrointestinal tract may take some time to recover from the damage caused by the virus. A highly digestible, low fibre ration is usually recommended.

CPV-2 is responsible for the most serious disease outbreaks and it can survive in the environment on inanimate objects for up to 5 months. Unfortunately the virus is resistant to many disinfectants - but it is sensitive to bleach (sodium hypochlorite) at a dilution rate of 1:30 bleach:water and this should be used to clean areas in which an infected dog has been kept after first washing the area with soapy water.

Prognosis

Puppies that survive CPV-2 infection usually do so within 7 days, but the younger the pups are when they succumb to the disease the poorer the prognosis

Puppies with CPV-1 infection usually die despite treatment, but they should be kept warm and given nutritional support as well as pups with CVP-2 infection.

This information in full can be found here: http://www.provet.co.uk/health/diseases/parvovirus.htm