“Parvo” is still, despite vaccination, an important disease and cause of death, especially among puppies. It is caused by canine parvovirus, a virus that attacks rapidly dividing cells. This virus is highly contagious, and is resistant to many disinfectants – specific parvocidal disinfectants must be used against this virus. The virus particles can also survive for several months in the environment, potentially infecting any dog that comes across it.
What dogs are at highest risk?
Young dogs between six weeks and six months of age, that are either unvaccinated or only partially vaccinated (for example, if they have had their first vaccines but not their second). Certain breeds are also at increased risk, including Rottweilers, German Shepherds and Dobermans.
Puppies under the age of six weeks are usually relatively safe, because they are protected by antibodies passed down by their mothers. However, this maternally derived antibody wanes and is gradually lost, usually between five and eight weeks old. If the mother has only a poor immunity, for example if her vaccines are not up to date, the immunity will be less complete and will fade earlier.
What are the symptoms?
Most parvovirus infections primarily attack the intestines, although there is a rarer form of the disease that attacks the heart, causing shortness of breath and sudden death.
The common symptoms include:
- Lethargy, depression and loss of appetite
- Bloody diarrhoea
- Abdominal pain
- Severe dehydration and shock
The diarrhoea has a characteristic foul smell, caused by death of the intestinal lining. You may even see small pieces of tissue in the diarrhoea as they are shed. At the same time, the dog’s immune system is severely impaired, making them prone to septicaemia.
How is it diagnosed?
There is a very simple test we can do with either blood or faeces. This will rapidly demonstrate the presence of the virus – it takes less than ten minutes to run this “Snap Test” in our lab, so we can even do it while you’re waiting.
What is the treatment?
Dogs with parvovirus are very, very ill, and require intensive care. Infected dogs will be admitted and placed in an isolation ward, to prevent them from spreading the virus to other patients. We place them on a drip to support their hydration and circulatory system. We will try to suppress the vomiting with medication, and we’ll usually put them on powerful antibiotics to prevent septicaemia. There is also a drug called interferon which, although expensive, does reduce the mortality rate by increasing the immune system’s response to the virus.
With aggressive and early treatment, approximately 70% of affected dogs can be expected to survive. Dogs who survive more than three or four days are likely to make a full recovery, and once recovered, they usually have a very strong immunity to the virus.
How can it be prevented?
Simple – vaccination! Parvovirus is defined by the World Small Animal Veterinary Association as one of the “core” vaccines that every dog should receive. Once the primary course and the first annual booster has been given, it provides protection for approximately three years.
Puppies in high-risk groups can be vaccinated from six weeks, and a triple vaccination protocol (i.e. at six, eight and twelve weeks against Parvo) can be useful. In addition, it is important that breeding bitches are fully vaccinated to protect their puppies.
Young puppies and unvaccinated dogs should not be exposed to even a recovered dog – after apparent recovery, the virus is still being shed for about ten days, and will place any unprotected dogs at high risk of infection. As a result, anywhere an infected or recently recovered dog has been should be disinfected with a suitable parvocidal disinfectant.