By ANDREA McCANN
Indiana Correspondent

INDIANAPOLIS, Ind. — The Indiana Board of Animal Health (BOAH) is cautioning Hoosier horse owners to take preventative action against two deadly equine diseases that have been found throughout the state.

Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV) have been found in mosquito populations in several Indiana counties, although no cases have been confirmed yet in horses. Dr. Tim Bartlett, equine director for BOAH, said there’s a preponderance of the mosquitoes in the northern- and southern-tier counties this year.

He explained the type of mosquito that carries the diseases is endemic to the northern part of the state, and weather conditions this year contributed to higher populations in the south.

“We particularly see more West Nile Virus mosquitoes during hot, dry conditions,” Bartlett said. “Wet followed by dry are the worst conditions. West Nile mosquitoes breed more in hot conditions when there are standing pools. When there are flood conditions, and it starts to dry out, but there’s no more rain to flush them out, they have more area to breed in.”

He said horse owners need to be proactive about eliminating potential breeding sites. Sources of standing, stagnant water should be drained. Stock tanks should be kept fresh, but emptying around the tank and creating swampy areas should be avoided. Small, swampy areas, old tires and buckets all make ideal breeding grounds for mosquitoes, Bartlett said.

Other preventative measures he suggests include keeping equine species sheltered at dusk, when mosquitoes are most active; trying not to leave lights on at night, or at least setting them to go on and off earlier in the evening; keeping the animals on sand; using fly repellent; and circulating air with fans.

“The best prevention is vaccination,” Bartlett said.

Vaccinating horses now, for the first time this year, may be too late to offer protection this season, but it’s better than leaving them unvaccinated. He explained that an animal’s immune system will build gradually after two doses of vaccine given three to six weeks apart. He added that late-season vaccines will give horses a jump-start on protection for next year.

“We suggest at least an annual vaccine,” he said. “In years like this, when you expect cases (of WNV and EEE), you should try to do it twice a year – in spring and fall.”

The initial vaccine should be boostered about three weeks later, he emphasized. Bartlett said equine owners – including people who own donkeys and mules – should set up a preventative health schedule with their local veterinarian. Dr. Benjamin Poehlein, co-owner of Sullivan County Animal Hospital, said the economy can have a detrimental effect on preventative care. He said animal owners are less likely to seek such medicine during poor economic times. He believes the U.S. ban on horse slaughter also has an effect.

“There are more neglected horses,” Poehlein said. “Neglected horses are not vaccinated, which leads to a population of unvaccinated horses that serve as a reservoir for disease.”

Bartlett said for the most part, Hoosier horse owners take good care of their animals; however, sometimes they become complacent or the economy does have an impact, and they try to get by with just one vaccine a year instead of two.

Owners who suspect an equine has already been infected with EEE or WNV should contact their veterinarian immediately, he said. A blood test and lab analysis can identify the diseases.

Horses infected with EEE, which causes central nervous system problems, may exhibit a variety of signs, including seizures or fever. WNV causes inflammation of the brain.

Symptoms of WNV include listlessness, stumbling, weakness of limbs and partial paralysis. Both diseases are incurable and may be fatal; however, supportive care is available.

Bartlett explained that horses are dead-end hosts for both diseases, meaning they cannot spread it. Humans are also at risk from the same mosquitoes, though, which infect equine. The mosquitoes contract it from infected birds.