Canine circovirus has appeared in Michigan, confirmed through testing at Michigan State University. Samples from two dogs tested positive, but officials noted that in both cases, other diseases -- parvovirus in one case -- were involved, and the AVMA has urged the public to remain calm. "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," according to an AVMA statement. Veterinarian Lindsay Ruland called attention to the issue, questioning whether a number of dogs she's treated -- six of whom died -- might have the same illness that is under investigation in Ohio. Experts with the AVMA note that circoviruses are known to infect avian species and swine as well.