Canine Parvovirus: Causes, Symptoms and Treatment

Canine parvovirus (parvo) affects all dogs, but unvaccinated dogs and puppies younger than four months are at the greatest risk. Highly contagious, it causes an infectious gastrointestinal (GI) illness in puppies and young dogs, and without treatment can be fatal.

Readily transmitted from one place to another on the hair or feet of dogs or by way of contaminated cages, shoes, or other objects, the virus attacks the lining of the intestine and bone marrow. This hinders a dog’s ability to absorb vital nutrients, resulting in dehydration and weakness. Sadly there is no cure for parvovirus, but vaccinating your dog or puppy against parvo is vital to protecting them from infection. 

Transmission and Symptoms

Although its origin is unknown, canine parvovirus is believed to have originated from feline panleukopenia virus, another highly contagious and severe infection that causes gastrointestinal, immune system, and nervous system disease in cats. Part of what makes parvo so dangerous is the ease with which it can be transmitted among dogs – most commonly by direct dog-to-dog contact and contact with contaminated faeces (stool), environments, or people. Due to it being resistant to various weather conditions, such as heat, cold, humidity, and dryness, it’s able to survive in the environment for long periods of time, which impacts its ability to spread. As a result of its high survival rate, the virus is able to contaminate kennels, collars and leashes, food and water bowls, as well as the clothing and hands of people who have been in contact with an infected dog. Even trace amounts of faeces from an infected dog may shield the virus and infect other dogs that come into contact with the infected environment. 

Some of the symptoms of parvovirus include severe vomiting, bloody diarrhea, loss of appetite, and lethargy. Persistent vomiting and severe diarrhea can cause rapid dehydration, while damage to the intestines and immune system can result in septic shock. Less common but equally vicious, the cardiac or heart form of the parvovirus attacks the heart muscle. A puppy will die suddenly or after a brief period of breathing difficulty due to a collection of fluids in the pulmonary system. The heart form is less common and attacks the heart muscles of very young puppies. Both, sadly result in rapid death. 

Diagnosis and Treatment

Diagnosis is routinely based on a dog’s symptom history, physical examination, and a faecal antigen test. Treatment is supportive on an inpatient or outpatient basis because a viral cure is not yet available.

Most deaths from parvovirus occur within 48 to 72 hours following the onset of clinical signs. If your puppy or dog shows any suspicious symptoms, you need to contact your veterinarian immediately.

Are Your Pet’s Vaccinations Up-to-Date? 

Puppies require a series of vaccinations to create an immunity to parvovirus. If they miss even a single booster, they are prone to parvovirus. If they do not continue to receive lifelong boosters as recommended by their veterinarian, their antibody levels are at risk of dropping too low, making them susceptible to parvovirus. 

Some dog owners choose to test their dog’s antibody levels with vaccine titers every year before getting the vaccinations. If antibody levels are low, vaccination is recommended.

Viral mutation can also lead to puppies being susceptible to other strains of parvovirus that are not contained in the vaccine. Owing to this, your veterinarian will need to revaccinate your puppy even if their records indicate they have had the vaccination.

Lisa Wallace

Freelance Writer & Editor • I’m a Cape Town-based writer working in education technology. I love people, but undoubtedly love felines more! I literally skip with glee when TEARS rope me in with a writing assignment – it’s a great pleasure to be able to use my craft to help their marketing team, in any small way I can.