Canine parvovirus is a devastating disease that can affect all dogs, but primarily infects puppies and young unvaccinated dogs. It attacks the rapidly dividing cells of the intestines and the bone marrow, and in very young puppies the virus can also infect the cells of the heart. Some of the symptoms you might observe with a parvovirus infection include anorexia (lack of appetite), listlessness, severe diarrhea and vomiting. The infection also causes an increased risk of secondary infection.
Infection with parvovirus occurs when a puppy is exposed to contaminated feces or to an object, such as shoes or a sidewalk, which has been contaminated by feces. The virus can live on contaminated surfaces or clothing for up to 5-6 months. Parvovirus becomes widespread throughout the body in 3-4 days. Young puppies (10 days to 6 months) are the most widely infected. Signs of canine parvovirus typically start with anorexia and lethargy and progress to diarrhea and vomiting. Puppies can often appear to have a painful abdomen (belly). Puppies that develop any of these signs should be taken to the veterinarian and examined as soon as possible. While parvovirus is a common cause of vomiting and diarrhea in puppies, other causes can include foreign material ingestion, gastroenteritis from other causes, parasites and many other diseases.
Testing for canine parvovirus is generally done with a sample of feces or a rectal swab. The in-hospital test is performed on a stool sample and gives results (positive or negative) within 10 minutes. A false positive result is possible if the dog has been recently vaccinated, so it is very important to give that information to your doctor to help him to assess correctly your dog. Like with any other test, false negative results are also possible. In addition to testing specifically for parvovirus, a veterinarian will generally recommend a complete blood count (CBC) to look at the number of white blood cells, red blood cells and platelets in the blood. The CBC will likely be rechecked every day or so to see if the numbers are improving. A chemistry profile allows for evaluation of kidney function, liver function and evaluation of electrolytes that will help guide in the treatment of the disease. X-rays or an abdominal ultrasound will help to look for an intussusception (telescoping of the intestines onto themselves) and evaluate for other causes of vomiting such as foreign material within the intestines.
Aggressive treatment is vital for puppies infected with canine parvovirus. Treatment generally consists of IV fluids to maintain hydration and replace fluid loss, antibiotics to help prevent against secondary infection, pain medication, anti-nausea medication and antacids. Puppies with parvovirus are generally kept in an isolation ward to prevent them from exposing other dogs in the hospital to the virus. Occasionally puppies need to have tubes placed to allow them to be fed a liquid diet. IV nutrition is used in those puppies that vomit continuously. A plasma or albumin transfusion is occasionally needed. Some puppies only need to be hospitalized for 1-2 days, but others may need to stay in the hospital much longer. Unfortunately parvovirus infection can be fatal, despite all intervention.
When they do recover, most dogs are able to go back to a completely normal life. After discharge from the hospital they may continue to shed the virus for 3-4 weeks. Puppies should be kept isolated for 4-6 weeks at home and unvaccinated or immune compromised dogs should not be exposed to the infected environment for 6 months.
Unfortunately there is no way to completely prevent a puppy from being exposed to parvovirus as it is so common in the environment, but minimizing their exposure until they are fully vaccinated should be attempted. The highest concentration of virus tends to be in environments where a known infected animal lives or at places with lots of dog traffic, such as the dog park or pet store. Keeping your puppy away from areas where other dogs frequent until fully vaccinated is a good strategy to reduce their risk of infection. The vaccine is very efficient, which is why we so rarely see the disease in adult dogs that have been adequately vaccinated. Puppies are usually first vaccinated when they are 6 to 8 weeks old. The vaccine needs to be repeated every 3-4 weeks until they reach 16 weeks old. Until they complete the full protocol, they are not completely protected and remain at risk of contracting the disease if they are exposed. A booster is usually given at 1 year, then every 3 years.
Vomiting and diarrhea are always a concern, especially in puppies. Whether you suspect parvovirus or not, if your puppy is not active and eating well, it’s time to make a trip to your veterinarian. And of course, Veterinary Emergency + Critical Care is here for you at any time of day and night. Reach us at 702.262.7070, or come see us, we are on the corner of Tropicana and Durango.