WNV in horses is treatable and vaccines are available.
“WNV is the leading cause of encephalitis in horses in the United States. State veterinarian Dr. Charles Hatcher said, “The risk of mosquitos transmitting the diseases carries well into the fall, not just the summer months.”
Hatcher advised, “avoid co-mingling your horses with unfamiliar horses, sharing surgical equipment, managing manure and disposal, eliminating standing water sources and applying insect repellants.”
Dr. Lew Strickland, UT Extension veterinarian, said, “Most veterinarians currently recommend that horses in Tennessee receive spring and fall booster vaccinations after the initial two-dose vaccine series. It is extremely important that horses initially receive two doses of the WNV vaccine at the time interval recommended by the vaccine manufacturer. Maximum protection does not happen until several weeks after the second, initial vaccination. If you are in a high-risk area, an additional booster maybe recommended by your veterinarian if this is the first time a horse is receiving the vaccine.”
Due to its prevalence, the American Association of Equine Practitioners considers the WNV a core vaccine, and recommends vaccination for all horses in North America independent of location, travel and management practices.
Equine infectious anemia, commonly known as “swamp fever” or “horse malaria,” has no treatment or vaccination. The virus is spread from horse to horse by biting, blood-sucking flies such as the horsefly and deerfly. The virus can also be passed from dam to foal, through natural breeding as a venereal disease, and by any transfer of blood from an infected horse to an uninfected such as the use of dirty needles or other equipment.
Control of the disease is through testing of horses to identify carriers of the virus. The Coggins test was developed in 1970 and is used as the standard diagnostic test to detect antibodies in the blood against the virus. This testing is part of a federal and state program to control this disease. The Coggins test is commonly required when moving horses within and among states. It is recommended to have your horse tested yearly starting at 6 months old. Any horses that are tested positive must be either euthanized or quarantined a safe distance from other horses.
Here are things that horse owners can do to help control spread of this disease, according to the U.S. Department of Agriculture:
• Use disposable syringes and needles. Follow the rule of one horse, one needle.
• Clean and sterilize all instruments thoroughly after each use.
• Keep stables and immediate facilities clean and sanitary. Remove manure and debris promptly and ensure the area is well drained.
• Implement insect controls. Avoid habitats favorable to insect survival.
• Do not intermingle infected and healthy animals. Do not breed EIAV-positive horses.
• Isolate all new equine brought to the premises until they have been tested for EIA.
• Get the required certification of negative EIA test status for horse shows, county fairs and other places where many animals are brought together.
For more information, contact the UT-TSU Extension Office in Wilson County at 615-444-9584. You can also find us on Facebook or visit extension.tennessee.edu/wilson. Ruth Correll, UT Extension-TSU Cooperative Extension agent in Wilson County, may be reached at 615-444-9584 or firstname.lastname@example.org.