Contagious Disease Control/ Vaccinations

With spring finally here many horse owners are beginning to think about the many adventures that they can have this year with their equine partner. When traveling to shows, trail rides, new barns or coming in contact with new horses there are a few things you should be sure your horse is protected against.

Contagious diseases are those that can be spread from one animal to another. Control programs should be targeted at reducing exposure to disease-causing agents and increasing disease resistance. To reduce contagious disease exposure to resident horses, it should be required that new horses to the property or horses that are traveling have a negative test for Equine Infectious Anemia (EIA, “Coggins Test”) and have been appropriately vaccinated and dewormed before they arrive. New horses should be received and maintained in an isolation barn or paddock for 30 days to ensure that sick horses or horses incubating a contagious disease are not inadvertently introduced into the farm population. The isolation area should be physically separated from the resident horses. Separate equipment and preferably separate personnel should be used to take care of the isolated horses. Isolated horses should be cared for after the resident horses. During the 30-day quarantine period, horses should be monitored daily for signs of contagious disease. Common signs to look for are decreased appetite or activity level, coughing, fever, and discharge from the nose or eyes.

Additionally, any resident horse that becomes ill with a potentially contagious disease should also be promptly isolated. Isolation should continue for at least 10 days after all symptoms are gone. Separate equipment and personnel should be used to take care of sick horses. If separate personnel are not available, sick horses should be tended to after the other horses on the farm. Stalls that have housed sick horses should be thoroughly cleaned, disinfected, and left empty for as long as possible before being used by other horses.

Disease resistance in horses can be enhanced by proper housing, feeding, exercise, and the use of vaccines. Vaccines are health products that trigger protective immune responses and prepare the vaccinated individual to fight future infections from disease-causing agents. There are many vaccines and vaccine combinations available for use in horses. The specific vaccines needed by a particular horse will depend on several factors, including the horse’s age, exposure to other horses, and geographic location. Your veterinarian will help you determine the vaccination program best suited for your horse.

In general, all adult horses should be vaccinated against tetanus, eastern and western encephalomyelitis (EEE and WEE), west Nile virus (WNV), and rabies each year. Horses that are exposed to other horses during shows, trail rides, etc. should also be vaccinated for influenza and equine herpes virus 1 and 4 (EHV- 1 and EHV-4). These vaccines may need to be boostered every three to six months for effective immunity. Pregnant mares should be vaccinated against EHV- 1 the fifth, seventh, and ninth months of gestation. Pregnant mares should also be boostered for tetanus, EEE, WEE, WNV, EHV-1, EHV-4, and Influenza, four to six weeks before foaling. Only “killed” vaccines may be used in the pregnant mare. Foals from appropriately vaccinated mares usually start their vaccinations when they are three to four months old. Foals from unvaccinated mares need tetanus antitoxin right after birth and should start their vaccines at two to three months of age. Many other vaccines are available, and may be recommended in your area. Again, work with your veterinarian to set up a vaccine protocol specific to your horse’s individual needs.

Adapted from Health Care for Horses, Scott Pleasant, D.V.M. Virginia Cooperative Extension.