By LEONARD GRAY

ST. ROSE – The threat of West Nile equine encephalitis among horses in the River Parishes area has some horse owners concerned but not concerned enough, according to local officials.

St. Rose veterinarian Dr. Randall Wegmann said the first case appeared in north Louisiana last year “and spread like wildfire.” When the vaccine finally appeared in September, most owners had their horses vaccinated.

However, the vaccine is only good for about six months or so, and need to be renewed, Wegmann urged.

“These owners tend not to think about this stuff until horses start dying,” he said.

LSU AgCenter veterinarian Dr. Steven Nicholson added West Nile has been joined by the early appearance of clinical eastern equine encephalitis, appearing in the Baton Rouge area. West Nile was found in birds in the same area as well, along with West Nile in horses in Cameron Parish.

“Mosquito populations may be larger this summer with the end of the drought in south Louisiana and the return to a normal rain pattern expected,” Nicholson continued.

“More mosquitoes could mean an increased risk of transmission of these viruses from birds to horses.”

With eastern encephalitis, infection is obvious within five days and death usually follows within two or three days afterward.

Early signs include fever and a droopy, sleepy appearance. Walking in circles, weakness and staggering soon follow. Then the horse lapses into a coma for several hours before death.

West Nile is not so obvious, Nicholson advised.

Signs include rear limb weakness and staggering. Recovery is possible, but 30 percent of infected horses die.

Foals can receive a passive immunity if their mares are vaccinated, but an active immunity could take longer to develop. If the mare was not vaccinated, the foal should be vaccinated in a matter of a week or so after birth.

“They say to start vaccinating before the mosquito season starts,” Wegmann said, “but tell me when that is!”

Vaccinations should be continued at least twice a year for the life of the animal. “Even horses vaccinated last fall should be re-vaccinated this spring,” Wegmann advised.