Canine parvovirus is a highly contagious disease most commonly caused by the virus known as canine parvovirus variation 2 or CPV2. The virus can infect dogs, foxes, coyotes, wolves, and jackals. Death can occur between two to three days following infection and vaccination to prevent this is highly recommended. The virus initially reproduces in the dividing cells of the lymph nodes and then move on to the intestines and the bone marrow, thus replicating further and suppressing the immune system. Dogs are more susceptible to contracting the disease when they are at a very young age: usually when they are under six months old because they have not yet developed a strong immune system. Particular breeds of dogs such as the Doberman and the Rottweiler have also been known to be more likely to contract the virus than other breeds. The most common forms of the virus are presented as cardiac or intestinal.
This life threatening disease can be spread via infected faeces entering the digestive system orally or from even everyday items such as clothing, bowls, car tyres, and fur. As a result, even “house dogs” that do not leave the home or come into contact with other dogs can catch the disease. Adult dogs are able to become carriers of the virus without showing any clinical symptoms and unknowingly pass it on to others.
It can survive away from the dog for several months in the right conditions and is very difficult to get rid of and so this is one of the reasons for vaccination. If a dog has been infected, most disinfectants do not work to kill the virus in the household although some veterinarians advise chlorine bleach as this has been shown to have some success. Obviously, this should not be given to the dog. The disease is not zoonotic, that is to say it cannot be transferred to humans.
The virus is known to attack the linings of the digestive system. As a result, the animal presents an inability to absorb fluids correctly along with some nutrients. Symptoms therefore include dehydration, bloody diarrhoea, vomiting, depression, fever, and loss of appetite. The symptom that is most noticeable is the strong unpleasant smell of the faeces. Some dogs may not show any symptoms but still die within three days of ingesting the virus. If the dogs do survive the infection they are usually relatively unhealthy for the rest of their lives.
The least common type is the cardiac form. Occasionally, months or even years after the initial symptoms canine parvovirus can attack the cardiac muscles. However, the virus can also attack the heart of puppies that contracted the disease whilst still in the womb. Vaccination has reduced the occurrence of this but if it is contracted at this time, the puppy usually dies a sudden death. The main symptom is difficulty breathing but even then it can be too late.
Treatment and Prevention
There is no cure against the parvovirus. Treatment involves treating the symptoms in the hope that the dog will be able to fight the infection with its own immune system. IV fluids are given to replace those fluids and minerals lost and prevent dehydration. Antibiotics may also be administered to prevent secondary infection. Treatment can last as long as week but even so, the dogs do not always survive.
As is the rule of medicine; prevention is better than cure. Vaccinations are available and highly recommended to all dog owners. Puppies should be given their initial vaccination at six to eight weeks old and only until a week after then final injection is given should the puppy be allowed to socialise. Annual boosters should also be given. If the dog has survived the parvovirus then it should be isolated for up to a month after it has recovered and its faeces cleaned up. Anything inanimate that may be contaminated should be cleaned thoroughly with chlorine bleach.
Diagnosis and Prognosis
The most common test is the ELISA test, which is used to show if there is any virus present in the faeces, and a white cell count is used to detect any drop in numbers. Biopsies can be performed if a dog has died and the veterinarians were unsure of the cause of death. The virus can then be seen under a microscope. The disease has a very high mortality rate if left untreated. Over 90% of dogs and puppies which have the parvovirus and are not treated die. However, if caught in time around 80% of the dogs survive although they may not lead very healthy lives.