What is it?
Parvo (or, more properly, Canine Parvovirus) is a severe, often fatal viral infection. Although nowadays it is most commonly seen in puppies, Parvo can affect adults as well if they are unvaccinated.
What causes it?
The Canine Parvovirus is transmitted in the faeces of infected dogs. The incubation period of the virus is 7-14 days; once the virus infects a new dog, it attacks both their immune system and their intestines, causing massive breakdown of the gut wall. This allows bacteria from the gut to invade the body, leading to septicaemia ("blood poisoning"). In rare cases, there may also be damage to the heart.
What dogs are at risk?
Any unvaccinated dog is potentially at risk. Disease is most commonly seen in puppies between 6 weeks and 6 months of age; up until 6 weeks, they are protected by their mother's immunity ("Maternally Derived Antibodies"). However, in some breeds (such as Rottweilers, Dobermans and possibly German shepherds) this maternal immunity lasts longer - this (counterintuitively) means that the puppies are at HIGHER risk of Parvo, as the maternal immunity may prevent them from responding properly to their puppy vaccines.
What are the symptoms?
The initial symptoms are lethargy and loss of appetite; this is followed by severe vomiting and diarrhoea. The diarrhoea is initially watery but rapidly becomes bloody and develops a foul smell, caused essentially by dead, decaying gut lining. In some cases, chunks of gut lining are passed in the diarrhoea. The dog will now become severely ill, collapse, and will rapidly go into septic shock and die without treatment.
How is it diagnosed?
There are rapid diagnostic tests available which we can carry out in minutes using a sample of faeces, or even a swab from the rectum, which will diagnose the presence of the Parvovirus.
How can it be treated or managed?
These dogs are incredibly ill and need full intensive care nursing - as well as isolation from all other dogs. High dose intravenous fluids via a drip will help combat the septic shock, and antibiotics will help prevent bacterial septicaemia. Anti-vomiting medications are also invaluable. Immune stimulating drugs (such as interferon), although expensive, can also be very useful in rallying the immune system; however, we would expect at least one in three affected puppies to die despite all treatment efforts.
Can it be prevented?
Yes - there is a highly effective vaccine available (although in certain breeds it may need to be given later than in most dogs). Once the dog has had their puppy course and an annual booster, the vaccine lasts for approximately three years before needing a booster.