A Case of Canine Parvoviral Enteritis (PARVO)

by Andrew LaVasser, DVM

One of the most common calls we receive at our emergency clinics, involves newly adopted puppies that suddenly feel bad and develop a diarrhea which becomes bloody. While there are many causes of diarrhea or even bloody diarrhea, one of the most common is an inflammation of the gastrointestinal tract (enteritis) caused by a specific virus named parvovirus. The disease itself is frequently just called PARVO. Few puppies can survive this disease without help so early identification and intervention with the appropriate treatment is key to survival.

Parvo is a highly contagious and transmission occurs when puppies are exposed to contaminated feces from another dog.  This virus is hardy and can live for months to years in the environment.  Once the puppy is infected, the virus attacks the intestinal tract and bone marrow.  After about one week the pup begins to feel bad, stops eating, usually begins to vomit, and, breaks with diarrhea that becomes bloody due to the extensive damage it does to the intestinal lining. Because bone marrow is affected, the very white blood cells the puppy needs to fight the infection are not available because they are produced in the bone marrow. Now the puppy cannot fight the infection, cannot eat due to nausea, and couldn’t absorb nutrients from food if it could eat due to the damage in its gastrointestinal tract. And, finally, it becomes dehydrated from the loss of body fluid in the diarrhea. No wonder that without treatment, most puppies die.

The disease can be identified by a simple blood test.  Other blood tests are needed to identify complicating factors such as immune-suppression and to monitor progression.

Statistically, puppies have a survival rate of 80-95% with treatment, and less than 10% survival rate without treatment.  Treatment is mostly supportive in nature and is necessary to re-establish proper hydration, to prevent systemic infection and to provide nutrition.  It is very intensive and will require several days to a week of hospitalization.

Vaccination is routinely given for parvo and it is very effective. However, some puppies can break with the disease before the vaccine can work and a few puppies will not develop a protective titer despite a good vaccination history.

Not all puppies with bloody diarrhea have parvovirus, but do not wait to find out. If your puppy develops bloody diarrhea, please contact your veterinarian immediately or the VRRH emergency clinic if your veterinarian is not available after hours. In fact, your veterinarian may refer your puppy to us for the round the clock intensive care that is required in most cases.

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Citation:

  1. Cote, Etienne; Clinical Veterinary Advisor 2nd Ed; Elsevier; 2011
  2. Ettinger, Stephen J., Feldman, Edward C.; Textbook of Veterinary Internal Medicine 7th ED; Elsevier; 2010
  3. Greene, Craig E.; Infectious Diseases of the Dog and Cat 3rd Ed; Elsevier; 2006