LANSING, Mich. -- A horse has tested positive for West Nile virus, the first such case of the year in Michigan, the state Department of Agriculture says.

 

Laboratory tests conducted in early August at Michigan State University confirmed the virus in the unvaccinated horse from Clinton County. The animal, which showed signs of stumbling and mild depression, since has recovered from the illness.

 

State officials say the case should remind state residents and horse owners to be on guard against the disease, which is carried by mosquitoes.

 

"While the risk of horses contracting the virus or developing severe disease is low, it is vital that Michigan horse owners know about WNV and follow some basic, but important, steps to protect their animals," Steve Halstead, the MDA's equine program manager, said in a statement.

 

Most horses bitten by carrier mosquitoes do not develop the disease, state officials said. Of those that do, about one-third develop severe illnesses and die.

 

Agricultural department officials said that safe, effective vaccines are available as an aid to prevent West Nile virus in horses.

 

Last year, 10 horses tested positive for West Nile in Michigan. In 2002, 341 Michigan horses tested positive.

 

A Kalamazoo County man was treated and released at a local hospital in June in the only documented human case of West Nile virus in Michigan this summer.

 

The virus has been detected in birds in more than 50 of Michigan's 83 counties so far this summer.