Early test results show no new parvo outbreak, MSU says

Unknown respiratory disease also strikes Michigan shelter

September 4, 2008 (published)
By Jennifer Fiala

East Lansing, Mich. — As panic dies concerning suspicions that a highly virulent or new strain of canine parvovirus hit at least 40 dogs in a Michigan shelter, the same facility now reports 50 dogs exhibiting signs of unidentified upper respiratory disease, possibly canine influenza.

That comes from Dr. Wendy Swift, veterinary medical director at the Humane Society of Kent County in West Michigan. While Swift says she’s trying not to rouse alarm, it’s her job to inform local veterinarians and the pubic about the possibility of disease outbreaks.

At press time, laboratory tests had not come back to identify the respiratory illness, and Swift notes that the shelter is “in super-isolation mode.” But Dr. Carole Bolin, director of Michigan State University’s Diagnostic Center for Population and Animal Health, says that of the suspected parvo cases she’s recently received, none have turned out to be canine parvovirus type 2c (CPV-2c), a variant initially confirmed in the United States in 2006 and, to date, undocumented in Michigan.

While Bolin won’t publicly state that the cases she’s investigating came from the shelter, Swift verifies that the Humane Society of Kent County sent samples there for strain typing.

“We’ve confirmed parvovirus in some of the animals, but we have no documentation here that the new strain infected them. So far, it’s not parvovirus 2c, but our work continues,” Bolin says.

According to Swift, additional test results are pending with Pfizer Animal Health’s diagnostic services, which also received Humane Society of Kent County samples.

Right now, definitive expert opinion concerning the existence of CPV-2c in West Michigan does not exist. Yet the mere possibility that it could be there has attracted a wave of media attention, prompted by an Aug. 20 alert from shelter officials linking the variant to the suspicious deaths of three canine intakes. Swift explains that she issued the press release when previously vaccinated dogs started testing positive for parvo on IDEXX Snap Tests.

“I know there is a such thing as non-responder dogs, but never in the five years I’ve worked here have I seen a vaccinated dog die of parvo,” she says. “We think seven (infected) dogs had been vaccinated, but I only got three verified, complete vaccine histories confirmed. If it were 25 to 35 unvaccinated puppies getting parvo, that would be a normal number. But to have 40 dogs test positive since June 1 — that worried me.”

Swift says that local veterinarians aren’t reporting huge parvo increases this season — information shared after the West Michigan Academy of Small Animal Practitioners called an emergency meeting on Aug. 27 to compare what local DVMs are seeing in private clinics. According to the group, immunized dogs are protected from CPV-2c, providing proper vaccination protocols are followed. The Michigan Veterinary Medical Association (MVMA), which issued an Aug. 28 alert to its membership, downplays the association between CPV-2c and the outbreak.

All indications are that this was "overly reported and not that big of a deal,” a MVMA spokeswoman says.

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