By KEVIN WALKER
Michigan Correspondent

LANSING, Mich. — The Michigan Department of Agriculture (MDA) announced last month that several new cases of pseudorabies (PRV) have been detected on a Michigan ranch.

An MDA laboratory confirmed that 19 sport swine tested positive for PRV on a game ranch in Saginaw County. PRV is a highly contagious viral disease of swine that causes newborn piglets to die. In rare cases, the disease can cause sudden death in cats and dogs and can affect cattle, sheep and deer.

The disease does not cause illness in people and is not related to rabies.

According to Nancy Frank, an assistant state veterinarian with the MDA, as more PRV-positive swine are found, the greater the chance that commercial market swine could also become infected. This would have a profound effect on the swine market.

“It’s an important issue, and it’s definitely a priority,” said David Marks, a wildlife disease biologist with the USDA’s Wildlife Services division. “We don’t want it to get into the commercial industry here.”

A critical point is that PRV is linked to the problem of feral swine, which is a new and growing problem in the state. Marks said if feral swine ever get to the numbers they are at in some southern states, it will create a range of problems. For example, he said the deer population would be affected because feral swine can out-compete deer for food and resources.

Kristine Brown, a laboratory technician with the Michigan Department of Natural Resources (MDNR) and the point person on PRV, said feral swine have been found in the vicinity of the game ranch where the most recent PRV-infected domestic swine were detected. In addition, five feral swine have tested positive for PRV in the state.
The most likely problem, she said, is inadequate fencing. She said there are no regulations at game ranches specifically targeted to fencing for swine, even though sturdy fencing is needed to keep pigs inside.

After a pig has gotten out, it can be difficult or impossible to find out from where it came. Although a ranch owner is legally responsible for an escaped pig, pigs are not ear-tagged, so they cannot be traced.

“We are now forced to take stronger and faster action,” Brown said.
State officials have taken the tack of contacting county prosecutors to get permission for hunters to kill feral swine on sight. Currently, 60 counties are open to the shooting of feral swine and the MDNR is working on the remaining counties to get permission.

“Once they are outside of that fence, they are no longer considered livestock,” Brown said.

A hunter, though, must have a valid hunting license in order to go out and hunt feral swine. Marks said the state is trying to test more feral swine for PRV, swine brucellosis and classical swine fever. The problem right now, he said, is that there isn’t a large number of feral swine. Once they are spotted and the MDNR is called to the site, the wild pigs have usually moved on. He strongly urges hunters that have taken a wild pig to get a blood sample as quickly as possible.

If no kit is available, he recommends that the hunter take a soda pop bottle with a cap, put some blood in it from the pig, store it in a cool, dark place and call the USDA to come and get it for testing.
Hunters may obtain a kit for this purpose for free, or get more information on the PRV issue, by calling the USDA’s Wildlife Services division at 517-336-1928 or their local MDNR office.