Most dog owners are familiar with canine parvovirus. However, the virus referred to as "parvo" is one strand, CPV2. The other strand, also referred to as canine minute virus, is less known.
Parvoviruses are a relatively small virus, consisting of a protein coat around a single strand of DNA. Despite its size, parvoviruses are remarkably effective, rapidly dividing host cells such as intestinal cells, bone marrow cells, cells of the lymph system and fetal cells. Because they are not enveloped in fatty tissue like most viruses, they survive very well in the environment, sometimes as long as nine months, and are hard to remove with disinfection.
The viruses are shed in very large numbers by infected dogs, particularly in the first two weeks. Unfortunately, the symptoms appear mild at first and may take 10 days to appear, so a large number of viruses are spread before the dog is quarantined. Early symptoms include high fever, lethargy and loss of appetite, which can be caused by many less serious viruses.
Canine Parvovirus 1 (CPV1)
The original canine parvovirus, CPV1 is most commonly seen in puppies ages 1 to 3 weeks. While many other species' parvoviruses have been known for decades, CPV1 is a relative newcomer, discovered in 1967 in Germany. Since it only affected puppies, it was not seen as much of a threat. The virus is contracted orally by the mother and passed to her fetuses. Puppies born with this illness show symptoms of severe diarrhea, difficulty breathing and anorexia. In severe cases, it can end in death. Though other diseases can cause it, diarrhea in puppies should be immediately checked out by your veterinarian.
Canine Parvovirus 2 (CPV2)
CPV2 is the disease commonly associated with the parvovirus since its mutation from CPV1 in the 1970s. This highly contagious disease is spread by direct or indirect contact with infected feces. If left untreated, CPV2 has a 91% mortality rate. With proper hospitalization, survival rate is 80%. Puppies and adolescents are most commonly affected because of their lack of immunity; however, adult dogs can occasionally contract the disease.
CPV2 appears in two different ways: cardiac and intestinal. The intestinal form, which is the most common, presents itself through severe vomiting and bloody diarrhea. The cardiac form results in cardiovascular failure or extreme respiratory problems in young puppies, who are most susceptible to the virus before vaccination, and often results in hospitalization.
Treatment for Parvovirus
There is no antiviral drug to cure canine parvovirus, so treatment involves a lengthy hospital stay that emphasizes supportive care. Parvo kills with dehydration or a bacterial invasion of the circulatory system, so treatment involves preventing dehydration and using antibiotics to kill bacteria that may infect the blood stream.
Preventing Canine Parvovirus
As with many viruses, prevention is much easier than treatment. Vaccinations are effective in preventing this disease and should be maintained even in adult dogs since adults can be carriers without showing symptoms. Before receiving proper vaccinations, puppies should not be socialized with any unknown dogs and should not be taken to places where strange dog feces might be or might have been within the last few months.
Though this disease is devastating, it is very easy to prevent with proper vaccination, so protect your dogs by following your veterinarian's vaccination protocols.