Canine parvovirus

Prevention is key to avoiding this contagious disease

Canine parvovirus

Monday, February 17, 2020 | NHS Staff

Canine Parvovirus is a highly contagious virus that can affect all dogs, but unvaccinated dogs and puppies younger than four months old are the most at risk. 

About parvovirus 

According to the AVMA dogs that are ill from canine parvovirus infection are often said to have "parvo." The virus affects dogs' gastrointestinal tracts and is spread by direct dog-to-dog contact and contact with contaminated feces, environments, or people. The virus can contaminate kennel surfaces, food and water bowls, collars and leashes, and the hands and clothing of peope who handle infected dogs. It is resistant to heat, cold, humidity, and drying and can survive in the environment for long periods of time. Even trace amounts of feces from an infected dog may harbor the virus and infect other dogs that come into the infected environment. The virus is readily transmitted from place to place on the hair or feet of dogs or via contaminated cages, shoes or other objects. 

Signs of parvovirus 

Some of the signs of parvovirus include lethargy; loss of appetite; abdominal pain and bloating; fever or low body temperature (hypothermia); vomiting; and severe, often bloody diarrhea. Persistent vomiting and diarrhea can cause rapid dehydraton, and damage to the intestines and immune system can cause septic shock. If your puppy or dog shows any of these signs, you should contact your veterinarian immediately. Most deaths from parvovirus occur within 48 to 72 hours following the onset of clinical signs. Immediate veterinary care is paramount.

Diagnosis and treatment

Parvovirus infection is often suspected based on the dog's history, physical examiation, and laboratory tests. Fecal testing can confirm the diagnosis.  No specific drug is available that will kill the virus in infected dogs, and treament is intended to support the dog's body systems until the dog's immune system can fight off the viral infection.  Treatment should be started immediately and consists primarily of intensive care efforts to combat deyhdration by replacing electrolyte, protein and fluid losses, controlling vomiting and diarrhea, and preventing secondary infections. Sick dogs should be kept warm and receive good nursing care. When a dog develops parvo, treatment can be very expensive and the dog may die despite aggressive treatment. Early recognition and treatment are very important in successful outcomes. Since parvo is highly contagious, isolation of infected dogs is necessary to minimize the spread of infection. Proper cleaning and disinfection of contaminated kennels and other areas where infected dogs are (or have been) housed is essential to control the spread of parvovirus.  The virus is not easily killed, so consult your veterinarian for specific guidance on cleaning and disinfecting agents.

Preventing parvovirus

Vaccination and good hygiene are critical components of prevention.   Young puppies are very susceptible to infection, particularly because the natural immunity provided by their mother's milk may wear off before the puppies' own immune systems are mature enough to fight off infection. If a puppy is exposed to parvovirus during this gap in protection it may become ill. An additional concern is that immunity provided by a mother's milk may interfere with an effective response to the vaccination. This means that even vaccinated puppies may occasionally be infected by parvovirus and develop the disease.

To reduce gaps in protection and provide the best defense against parvovirus during the first months of life, a series of puppy vaccinations should be administered. Pups should receive a dose of canine parvovirus vaccine between 14 and 16 weeks regardless of how many doses they received earlier, to develop adequate protection. 

To protect adult dogs, pet owners should be sure that their dog's parvovirus vaccination is up to date. Consult your veterinarian about the recomended prevention program.

Until a puppy has received its complete series of vaccinations, pet owners should use caution when bringing their pups to places where dogs congregate (eg: pet shops, dog parks, puppy and obedience classes, doggy daycares, kennels and grooming establishments). And contact with known infected dogs should be strictly avoided. 

Even with proper vaccinations, a small percentage of dogs do not develop protective immunity and can remain suceptible to infection. So a good rule of thumb is to not let your pup or adult dog come into contact wtih the fecal waste of other dogs while walking or playing outdoors. 

Prompt and proper disposal of dog waste is one way to help limit the spread of dog diseases.

Finally dogs with vomiting or diarrhea, or dogs exposed to ill dogs should not be taken to kennels, show grounds, dog parks, pet stores or other areas where they will come into contact with dogs. And unvaccinated dogs and pups should not be exposed to ill dogs or those with unknown vaccination histories.

If you are in contact with sick or exposed dogs you should avoid handling other dogs, or wash hands and change clothes before doing so.