AVMA News

Mystery illness identified as canine parvovirus

The mysterious parvolike illness seen in several dogs in northern Michigan has been identified as canine parvovirus, state officials announced Aug. 24.

The confirmation by the Michigan State University Veterinary Diagnostic Laboratory comes after initial tests failed to characterize the highly contagious virus.

Michigan state veterinarian Dr. Nora Wineland said in a public statement that the infected dogs did not have a history of complete vaccination.

A 4 month old puppy with an IV line inserted into his front leg administering fluids and immunoglobulin. Quarantined and isolated due to Canine parvovirus.


“We have a highly effective vaccine available to help protect dogs from the virus,” Dr. Wineland said. “Dogs that are not fully vaccinated against this virus are the most at risk.

“Dog owners across Michigan must work closely with their veterinarians to ensure their dogs are appropriately vaccinated and given timely boosters to keep their pets safe and healthy.”

In the same press release, Dr. Kim Dodd, director of the MSU diagnostic laboratory, described the situation as “complex,” explaining that although the dogs displayed clinical signs suggestive of parvovirus, they consistently tested negative on point-of-care tests performed in clinics and shelters.

“Screening tests for parvo are done to help guide immediate isolation, disinfection, and treatment protocols,” Dr. Dodd said. “While those tests are valuable in the clinical setting, they are not as sensitive as the diagnostic tests we can perform here in the laboratory. We continue to further characterize the virus in hopes of better understanding why those animals were testing negative on screening tests.”

The Michigan Department of Agriculture and Rural Development is encouraging dog owners to keep up with routine vaccinations, especially those living in or traveling with pets to the northern part of the state, by ensuring dogs are vaccinated against canine parvovirus, rabies, canine distemper, adenovirus, parainfluenza, and leptospirosis.

Additionally, experts recommend having puppies fully vaccinated before interacting with other animals and keeping them at home and away from other dogs if they are exhibiting any signs of illness and contacting a veterinarian.

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