April 25, 2007

 

Wisconsin reports second pseudorabies case

 

 

A second swine herd has tested positive for pseudorabies in Wisconsin's Madison County, state veterinarian Dr. Robert Ehlenfeldt said.

 

Eleven animals from Loyal farm tested positive for the disease at Wisconsin Veterinary Diagnostics Laboratory as the farm had bought an infected boar for breeding. The Loyal farm is outside the five-mile radius around the first infected herd in Greenwood.

 

The 20-animal herd has already been quarantined.

 

Ehlenfeldt said they will continue the investigation to check whether other herds are infected and to find the source of the infection.

 

The Department of Agriculture, Trade and Consumer Protection will work with the owner to develop a plan to destroy the animals and clean and disinfect the property. Because the disease poses no health risk for humans, the slaughtered animals can be consumed.

 

Quarantines will be delivered in the next few days to farms with swine within five miles of this second herd. Ehlenfeldt said the quarantine stops movement of live hogs to or off the farms, except for slaughter.

 

Herds on these premises will be tested for pseudorabies by May 5 and quarantines will be released for farms where herds test negative. Swine within two miles of the infected herd will be retested in one to two months after the infected farm is cleaned and disinfected. It's not yet determined how many swine herds there are in the five-mile area.

 

Ehlenfeldt said the US Department of Agriculture is deciding whether Wisconsin can maintain its pseudorabies-free status for trade purposes with its second infected case. Michigan has already banned Wisconsin swine imports. 

 

Pseudorabies is caused by a virus that enters the pig's system through its snout and is passed between pigs in mucus and saliva. It can be passed between pigs in close physical contact or in shared food that has been contaminated with mucus and saliva. Manure contaminated with mucus and saliva and tracked between farms may spread the infection, and in very rare circumstances, may be transmitted airborne up to a mile.

 

Pseudorabies often kills newborn pigs, and causes abortion or stillbirth in sows. On adult hogs, it causes respiratory signs and can carry the virus without symptoms and without transmitting it until stress or other factors activate it.

 

Other species including cattle, goats, sheep, horses, cats and dogs can contract the virus from pigs, most commonly by bites. They die within 48 to 72 hours, often showing symptoms similar to rabies though it is not related to rabies virus. These animals however do not transmit the disease.

 

Besides the disease threat, pseudorabies poses an economic threat to producers, because a loss of Wisconsin's pseudorabies-free status would mean they had to test for the disease before shipping animals out of state. In 2005, Wisconsin producers shipped 182,000 swine out of state. Wisconsin's pork production in 2005 was worth US$120 million, with a total swine herd of 430,000 animals.