(Ann Zaniewski/Detroit Free Press) - Two cases of a newly identified dog virus have shown up in Michigan, but researchers at Michigan State University said Friday that it's not clear whether the ailment has killed any dogs.
The university's Diagnostic Center for Population and Animal Health said it found canine circovirus in samples from two dogs that veterinary clinics submitted. Acting director Thomas Mullaney said both animals were infected with other organisms as well, so it's uncertain whether the virus caused their sicknesses.
Veterinarians at the Emergency Veterinary Hospital in Ann Arbor say they believe at least four dogs treated at the clinic in recent months died after contracting canine circovirus.
All of the sick dogs were found to have severely inflamed intestinal tracts, an infected or abscessed pancreas and enlarged abdominal lymph nodes, Dr. Lindsay Ruland, owner and chief of medicine at the hospital, said in a news release. They also had varying degrees of lethargy, vomiting and diarrhea.
Circoviruses are small viruses that have been known to infect birds and pigs, according to the American Veterinary Medical Association. Canine circovirus was first reported in June 2012, and there is no vaccine for it.
"Currently, circovirus by itself is not associated with a specific disease process," Mullaney said. But it has been shown to cause disease when combined with other viruses or bacteria in other species, including pigs.
The veterinary association says circovirus was suggested as the culprit behind a series of dog illnesses and deaths in late August and early September in Ohio, but the virus is no longer being considered as the primary cause of the illnesses. The Ohio Department of Agriculture is investigating.
The Michigan Department of Agriculture and Rural Development also is investigating, examining cases of illnesses similar to those seen in Ohio, according to the veterinary association. The Emergency Veterinary Hospital submitted samples toMSU for circovirus testing.
"Although we still have a lot to learn about this circovirus, there's no cause for panic," reads information on the association's website. "We know that dogs infected with circovirus don't always become ill, but we don't know how much of the virus they may shed in their stool or how much risk these dogs present as sources of infection for other dogs."
Ruland said a pet that exhibits significant lethargy, loss of appetite, abdominal pain, vomiting or diarrhea should be taken to a veterinarian immediately.
Experts don't know how dogs are being infected, although the highest risk of spreading viruses comes through contact with an infected animal.
Contact Ann Zaniewski: firstname.lastname@example.org. The Associated Press contributed to this report.