MISSISSIPPI STATE -- Keeping up with equine vaccination schedules may seem like an expensive inconvenience, but protected horses likely will avoid more serious and costly health problems.

"Horses in Mississippi need to be vaccinated against several diseases, including West Nile virus, Eastern and Western encephalomyelitis, tetanus and influenza. Optional vaccinations include those for rabies and strangles," said Dr. Stanley Robertson, Mississippi State University Extension Service veterinarian. "Vaccinations almost always prevent diseases, and it's better for the horses' health to vaccinate them instead of taking the chance of them getting a disease that could cause serious illness or even death."

The veterinarian said the vaccinations for rabies and strangles, a highly contagious bacterial disease, are optional because some horses are less likely to come into contact with those diseases or because negative side effects are associated with the vaccinations.

Whether or not a horse needs these vaccinations depends on its environment and region. The decision to vaccinate against these diseases should be made in consultation with a licensed veterinarian.

"Most people in Mississippi do not vaccinate for rabies because equine rabies is uncommon in this area," Robertson said. "But it's best that a vaccination schedule be recommended by a veterinarian, who will adjust that schedule so that it is specific to each individual horse."

MSU's College of Veterinary Medicine veterinarians recommend adult horses receive the optional rabies vaccination annually. Vaccinations for tetanus, Eastern and Western encephalitis, West Nile virus, influenza and types 1 and 4 herpes virus should be given two to four times per year. The optional strangles vaccination is needed one to two times annually. Foals and brood mares require more complex vaccination schedules.

"Horses should visit a veterinarian at least annually to receive needed vaccinations and to be checked for internal parasites," Robertson said. "Some horses, including brood mares and work or show horses, should be evaluated more often, at least two or three times a year. Vaccinations should be given either by a veterinarian or according to a veterinarian's recommendation."

Besides keeping vaccinations current, horse owners can help prevent mosquito-borne illnesses like West Nile virus and equine encephalitis by discouraging mosquito breeding activity in and around stabling areas. Eliminate standing water and clean water tanks or other sources of drinking water at least weekly.

"Improving the overall cleanliness of the premises also can limit vector activity, so frequent removal of manure and removing or trimming weeds can be beneficial," Robertson said. "In addition, keeping horses indoors during peak mosquito feeding times, such as at dusk and dawn, can cut down on the chances of getting West Nile and other viruses. Turning off barn lights or using fluorescent lights can minimize the attraction of adult mosquitoes into barns."

Keep air moving in stabling areas by using fans, and apply insect repellents that contain permethrins to horses, especially during peak mosquito feeding times.

Extension entomologist James Jarratt advised taking precautions to avoid mosquito bites in animals as well as humans, especially during peak mosquito hours.

"If you're outside early in the morning or late in the afternoon, wear long pants and long-sleeved shirts," Jarratt said. "Apply an insect repellant that contains DEET to all exposed skin."

Follow label directions when applying DEET, and keep it out of the eyes. DEET is a repellant, not an insecticide, and keeps mosquitoes from landing and feeding on people.

"DEET is the most effective product on the market," Jarratt said. "Some other products have some mosquito repellancy, but none as much as DEET. Citronella candles are popular outdoor repellants, but breezes reduce their effectiveness by diffusing the substance in the air."