Horse sense

Local and state veterinarians are recommending horse owners vaccinate their animals against the West Nile virus as soon as possible this year (Photo by Tim Jaynes, Staff)

Spring is the time to vaccinate horses against West Nile disease

SIKESTON -- Last-minute vaccinations and unexpected worries can all be avoided this year, state and local veterinarians say -- as long as owners have their horses vaccinated against the West Nile virus before summer hits.

"Now is the best time to get your horse vaccinated against the West Nile virus," noted Dr. Jeff Lawrence of North Ridge Veterinary Hospital. "It's better to be safe than sorry."

Studies show that 95 percent of properly vaccinated horses avoid illness if exposed to the virus, while more than 80 percent of unvaccinated horses develop an infection. The virus is fatal in about 30-40 percent of horses that contract the disease.

"We are expecting to see a large number of horses and some people to be infected by the virus this year," said Dr. Taylor Woods, state veterinarian and director of the state's Division of Animal Health.

Horses that were not vaccinated for West Nile virus last year or animals that received only one shot, this year will need two shots within six weeks of each other. Horses that received two vaccinations last year will only need one booster shot this year, Woods said.

"We're also telling horse owners that if the summer turns out to be really hot and the virus is as widespread as it was last year, they may want to consider a third vaccination," Woods said.

Spring is the ideal time to get the West Nile virus vaccination since it's also the time horses receive their routine vaccinations, Lawrence noted.

And although the vaccination is good for one year, Lawrence recommended those whose horses were vaccinated at the end of the summer last year to receive a vaccination again this spring. That way, he said, they can regulate their vaccination schedules.

West Nile is a virus that causes brain inflammation. Mosquitoes contract the virus by feeding on infected birds, then spread the disease by biting humans, horses, birds and other host animals. Last year, 917 cases of horses infected with West Nile virus were reported to the state veterinarian's office.

"West Nile is a nasty neurological disease," Lawrence said, who saw West Nile virus for the first time in Fruitland last year. "The horses (with West Nile virus) I've seen had their heads pressed against something like a barn door or wall, because they've had such severe headaches."

Horses infected with the virus display a variety of symptoms, including listlessness, stumbling, weakness in limbs and partial paralysis. Infected horses can be treated, and most make full recoveries.

Dr. Jim Pratt of the Animal Health Center agreed now is the perfect time to get horses vaccinated against West Nile, but added it's never too late to receive the vaccination.

After the horse receives both booster shots, it takes about two months for full protection to take place, Pratt estimated. So anyone vaccinating their horse in April won't have full protection until June, when the weather is typically hotter and mosquitoes begin to swarm and bite their prey.

In addition to the West Nile vaccine, horse owners should take other precautions, such as controlling the parasite or mosquito population on their farm, Pratt said.

"Bring your horses in at peak mosquito feeding times such as at dusk and early morning," Pratt suggested. "Run a fan later on in the evenings because mosquitoes are weak fliers and use fly sprays and repellents."

Woods also recommended removing sources of stagnant water, such as containers and old tires, and modify low-lying areas where mosquitoes might breed and cleaning water troughs as often as possible or at least once a month.

At this point, it's only the second year of West Nile in Missouri, Pratt noted. So it's difficult to determine how big the mosquito population will be this year or how much the area will be affected by the virus.

But whatever happens, at least it's possible for residents and their animals to be ready for the influx of mosquitoes and the deadly virus this year.

"Last year's breakout made people a lot more conscious of the virus," Lawrence said. "It wasn't here and then all of a sudden, bam! It was in Missouri and the vaccinations started up. This year there's more time to prepare."