Why are dozens of dogs suddenly dying in northern Michigan?

Officials in northern Michigan believe they have now identified a mysterious illness that has killed more than 50 dogs in the area in recent weeks. Most of the dogs that died were less than two years old and are died within three days of showing symptoms.

Despite affected dogs testing negative for the disease, the Michigan Department of Agriculture and Rural Development have announced that canine parvovirus is most likely to blame.

Melissa Fitzgerald, director of the Otsego County Animal Shelter, said that despite the preliminary test results, canine parvovirus was their “best guess” of the cause of death. She speculated that it could be a new strain of the canine virus.

What is canine parvovirus?

The virus is a contagious disease that is particularly dangerous for younger dogs, with puppies aged between six weeks and six months most at risk. Researchers have found that parvovirus is highly infectious and attacks cells in a dog’s intestine that prevent them from absorbing vital nutrients.

Affected dogs will soon become weak and dehydrated. Key symptoms of the illness are loss of appetite, vomiting, diarrhoea with blood in it, fever, collapse and depression.

While younger dogs are most at risk, parvovirus vaccines are largely successful in preventing them from falling seriously ill as a result. The weakening effect of the virus debilitates the victim’s immune system and prevent them effectively fighting the disease.

BlueCross recommends that puppies are vaccinated against parvovirus from the age of six weeks, with a second dose coming two weeks later. They will then require a booster vaccine at one year old, and vets often advise yearly booster shots to supplement the protection.

How contagious is canine parvovirus?

The disease is highly contagious in dogs but does not transmit to humans or to other types of animals, according to the Michigan state health authority. In canines the virus spreads in dog-to-dog contact with contaminated faeces and environments.

There is no drug known to kill parvovirus in infected dogs so the vaccination effort is particularly important. Once a dog has become infected the treatment tends to focus on supporting bodily systems, typically by replacing electrolyte, protein and fluid losses, to aid the immune response.

But given that the strain responsible for the recent outbreak appears to be different to ones previously recorded, experts are working on developing new ways of identifying the virus in dogs to offer treatment sooner.

“Screening tests for parvo are done to help guide immediate isolation, disinfection, and treatment protocols. 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,” said MSU Veterinary Diagnostic Laboratory Director Kim Dodd.

“We continue to further characterize the virus in hopes of better understanding why those animals were testing negative on screening tests.”