Why You Need to Vaccinate Your Pet Dog Against Parvovirus

Canine Parvovirus (CPV) is a highly contagious viral disease of dogs that commonly causes acute gastrointestinal illness in puppies. The disease most often strikes in pups between 6 and 20 weeks old, but older animals are sometimes also affected.

Cause

The virus that causes the disease known as ‘parvo’, canine parvovirus type 2, first emerged among dogs in Europe around 1976. By 1978 the virus had spread unchecked, causing a worldwide epidemic of myocarditis and inflammation in the intestine (gastroenteritis). We now know the virus is not limited to dogs, but is capable of causing infections in wild canines such as coyotes and wolves, and other wild animals, including foxes, racoons and skunks. CPV is related to Feline panleukopenia virus (FPV), a virus that has been known since the 1920s to infect cats and mink and other animals.

How can a dog become infected?

Canine parvovirus can be found in almost any environment, but not every dog who comes into contact with the virus becomes infected. Several factors come in infection, including the immune status of the dog and the number of viruses the dog is exposed to. If the combination of factors is just right and a dog does become infected, a specific sequence of events is begun as the virus attacks the body.

What happens during infection ?

Once a dog is infected, there is an incubation period of three to seven days before the onset of first symptoms. Inside the dog, CPV needs the help of rapidly dividing cells in order to successfully cause disease, and the virus usually begins by attacking the tonsils or lymph nodes of the throat. Once inside the lymph nodes, the virus typically invades lymphocytes ( a type of white blood cells) for one or two days, creating many copies of itself. These viruses hitch a ride inside the lymphocytes, where they are sheltered from the  host defenses, and enter the bloodstream. Many of these CPV infected lymphocytes are ultimately killed, causing a reduction in the number of circulating lymphocytes, a condition called lymphopenia.

Once in the bloodstream, the virus aging targets rapidly dividing cells, hitting hardest in the bone marrow and in the cells that line the walls of small intestine. In very young dogs, CPV can also infect the heart, leading to inflammation of heart muscle, poor function, and arrhythmias.

Symptoms and complications- Symptoms often associated with CPV include lethargy, depression, and lack of appetite, followed by a sudden onset of high fever, vomiting, diarrhoea. If the dog is experiencing bouts of bloody diarrhoea and vomiting, CPV is only one of several potential culprits.

Test and diagnosis

By far the most common and most convenient method of testing for the presence of CPV is the faecal ELISA test. The CPV faecal PCR test detects small pieces of viral DNA that are specific to CPV in the stool of an infected dog.

Treatment

Treatment options for dogs suffering from CPV involve supportive care and management of symptoms. Treatment options will vary, depending on how sick the dog is, but certain aspects are considered vital for all patients.

A hospital is often necessary so that the dog can receive intravenous fluids and nutrients to replace the vast quantities lost via vomiting and diarrhoea. An intravenous drip is preferred because the digestive tract of stricken dogs is usually in distress and can’t tolerate or absorb what the dogs need. Antibiotics may be appropriate therapy for a dog suffering from CPV.

Prevention

Since the advent of number of effective canine vaccinations for CPV, this infectious disease has become much less of a threat to dogs. This does not mean, however, that CPV does not remain a serious problem, and vaccination of your dog should not be considered an option- it is a must. These shots are given every 3-4 weeks from the time a puppy is 6 weeks old until he is at least 16 weeks of age.

The parvovirus is extraordinarily hardy. They are capable of surviving for months outside an animal, even through the winter, and resistant to most household cleaning products. Infected dogs can shed vast numbers of viruses, making it difficult to disinfect an area once it has been exposed to an infected dog. These facts highlight the importance of isolating any dog that is infected with CPV from other dogs.

Bhaskar jyoti Deka
College of veterinary science,
Khanapara