New Parvo Variant?

In August of 2022, the veterinary diagnostic lab at Michigan State University reported a “Parvo-like illness” in 30 dogs. The illness turns out to be…Parvovirus. In this case however, most of the dogs had been tested and deemed negative for Parvovirus at some past point with a veterinary screening test (commonly called SNAP or ELISA tests).

The experts at Michigan State University are unsure why this false negative occurred. Generally speaking there may be a few explanations for the false negative:

• The snap test used was expired or defective

• The involved dogs were not shedding virus particles at the time the SNAP test was administered

• The test procedure or sample collection were flawed and/or misread

• This is an alternate strain of Parvovirus which does not shed in feces, or sheds a virus antigen not recognized by the test.

MSU veterinarians say that a dog fully vaccinated against Parvovirus appears to have immunity; all of the dogs that died of this “new” variant had no, or incomplete, vaccinations. A fully vaccinated dog will have had a series of 3 vaccinations (age-dependent) as a puppy, another vaccination at 1 year old, and a vaccination every 1 to 3 years thereafter depending on your veterinarian’s recommendation.

Remember that canine Parvovirus is endemic and dogs have daily exposure to this virus. It is particularly a problem in puppies and bull terrier breeds appear to have a higher incidence rate (for unknown reasons).

If your dog exhibits the following, it is a medical emergency requiring immediate care:

• Lethargy or unwillingness to eat combined with fever (102.5 or higher)

• Vomiting or diarrhea that doesn’t resolve in less than 12-24 hours (The age of the dog makes a difference here. Very young and very old dogs should be on the 12 hour end of that spectrum.)

• Vomit or diarrhea which contains blood

Take care of your best friend! Get him or her vaccinated!