Signs and Symptoms


Parvovirus is most commonly seen in intact animals under the age of 6 months. Certain breeds tend to be more susceptible such as Rottweillers and Doberman Pinschers.

 General signs include lethargy and increase in rectal temperature. There are two main forms of CPV. The most common is the enteritis form. Very young animals may develop the less common second form which affects the cells of the heart and often can be fatal.1 In both cases complications may arise due to secondary bacterial infections.


Early GI signs include severe diarrhea and vomiting. Pacing, general discomfort and drooling are prodromal signs. The diarrhea and vomit often starts as a yellow-grey colour but may contain blood as the disease progresses. Projectile vomiting is not uncommon in later stages. Dehydration is a major concern and treatment often emphasizes the importance of fluid therapy.
Very young animals may have the virus infect the still dividing cells of heart. Animals present with much more acute signs and often will not present with diarrhea or GI upset. Generally lethargy, weakness, and anorexia usually precedes collapse of the animal. Puppies that have this form often die within 24 hrs of presenting clinical signs.  If an animal survives the initial infection it may die of heart failure weeks to months from the time of recovery. Surviving dogs tend to have myocardial fibrosis and permenant heart damage.3 glassdog
 Postmortem examination of the enteritis form reveals lower and middle small intestines dilated and containing watery and flocculant material. Hemorrhage along the lumen is not uncommon. Bone marrow depletion is seen in both forms. On necropsy of the myocarditis form the heart can be dilated with ill-defined pale areas in the myocardium. The heart may also be pale and flabby with areas of fibrosis in chronic cases.2

1The Merck Veterinary Manual.  9th Edition.  Eds: Kahn C, Line S.  Published by Merck & Co., Inc.  Whitehouse Station, NJ.  2005.

  2 Bastianello, S.S. Canine Parvo myocarditis: clinical signs and pathological lesions encountered in natural cases. Journal of the South African Veterinary Association. 1981. June. 52(2):105-8

Lenghaus C, Suddert MJ, and Finnie JW.  Acute and chronic canine parvovirus myocarditis following intrauterine inoculation. Australian Veterinary Journal.1980 Oct;56(10):465-8