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ASG Specialties:

  • Hip Dysplasia
  • Patella Luxation
  • Medial Patella Luxation
  • Elbow Dysplasia
  • Fragmented Coronoid Process
  • OCD Osteochondritis Dissecans Fractures
  • Arthritis
  • Ruptured Cruciate Ligament
  • Ruptured Cranial Cruciate Ligament
  • Ruptured Anterior Cruciate Ligament

Canine Parvovirus (Parvo)

Canine Parvovirus

Canine parvovirus (Parvo) is a highly contagious viral disease between dogs that is a common cause of diarrhea and vomiting. The virus seeks out rapidly dividing cells, which can include cells in the intestines and bone marrow.

By Emilie Chaplow, VMD
Diplomate American College of Veterinary Internal Medicine


The virus affects the ability of the intestinal cells to absorb nutrients, leading to vomiting and diarrhea. The barrier separating the digestive bacteria from the blood stream then breaks down. The diarrhea becomes bloody and bacteria can enter the body, causing widespread infection. Since the virus also destroys the bone marrow, the immune system is unable to fight the infection.

All dogs are susceptible to parvovirus, but puppies are most at risk. Parvo is usually spread from dog to dog through exposure to contaminated feces. The virus is shed in the feces for the first two weeks after initial infection. Parvo can also be spread through contact with contaminated objects, such as toys and bedding. The virus is very stable and is resistant to most disinfectants. It can last in the soil for over a year.

Clinical Signs

The most common symptoms of parvovirus are vomiting, bloody diarrhea, weight loss, and lack of appetite. Due to the severe vomiting and bloody diarrhea, these dogs can get extremely dehydrated.


Parvo is typically diagnosed with the Fecal Parvo ELISA test or Parvo Snap test. This test requires a fecal sample and usually shows a positive or negative result in approximately 10 minutes. Other tests, such as a complete blood count (CBC) to see if there is a drop in white blood cells secondary to bone marrow destruction are also typically performed, along with x-rays and additional bloodwork.


Since the disease is a virus, there is no real cure or antidote, only symptomatic treatment. Treatment is based on curing the symptoms and preventing secondary bacterial infections. Ideally, infected dogs should be hospitalized for this treatment. Treatment can include IV fluids, antibiotics, anti-nausea medication, and supplemental feeding. With treatment and hospitalization, survival rates can approach 80% (


Canine Parvovirus (CPV) vaccine is considered a core vaccine and is recommended for all puppies and dogs. For the initial puppy vaccine, one dose of the CPV vaccine (often given in a combination vaccine) is recommended every 3-4 weeks from 6-8 weeks of age, with the final booster given no sooner than 16 weeks of age. For dogs older than 16 weeks of age, two doses of the vaccine given 3-4 weeks apart are recommended. It is important that you follow your veterinarian’s vaccine protocols. These vaccines will also need to be boostered according to your veterinarian’s recommendations. Puppies should be restricted from public outdoor areas until they complete their vaccine series.


If your dog is being treated for parvovirus, it is extremely important that you bleach all surfaces your dog has come into contact with. Your dog will also continue to be a contagion risk to other dogs for at least two months after the initial recovery.



Animal Specialty Group

VMD, Diplomate American College of Veterinary Internal Medicine

Dr. Emilie Chaplow received her Veterinary Medical Doctor degree from the University of Pennsylvania in 2001, and became board certified in 2005. She is skilled in endoscopy, abdominal ultrasound, bone marrow aspirates, feeding tube placement (PEG and E-tube), CSF taps, joint taps, arterial blood gas, and numerous other areas of internal medicine.

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