As spring time approaches and weather becomes warmer, more horses are out on trails and in pastures leading to exposure to ticks that carry Lyme disease. Certain sections of the USA are more commonly infested by ticks including areas in California, north western states, and eastern states.
Lyme disease is a bacterial illness caused by a spirochete called Borrellia burgdorferi. The bacteria are spread by a tick, commonly called the deer tick, and can infect pets, horses, cattle, as well as humans. Lyme disease in horses is quite common for animals living in high risk areas.
Equine Lyme disease is not easy to identify, as less than 10% of the horses will show any symptoms at all. The most common symptoms are lameness and changes in the animal's behavior. Usually, the animal shifts frequently from limb to limb and shows signs of general stiffness. The horse can also show signs of irritability and refuse to work.
Lyme disease in horses is a tricky diagnosis even for experienced veterinarians, since these animals are prone to muscle and joint injuries, making it difficult to relate such problems immediately to a bacterial infection. Also, the blood test can only show that the animal has been exposed to the bacteria and its immune system reacted, but this doesn't mean that the disease has been triggered.
The only treatment available is based on antibiotics, and treatment takes several weeks. Most equines with the disease respond rapidly to treatment. Anti-inflammatory drugs can be used to ease the pain and stiffness and stomach medicine may help the horse cope with the antibiotic treatment.
At present, there is no licensed vaccine for equine Lyme disease, but, since vaccines have been developed for dogs and one also exists for humans, there are hopes that one for hoses will follow shortly. Until then, the only prevention method is the tick control.
Equines should be groomed frequently and any ticks removed in a timely fashion. Ticks are most likely to be found on the head, throat, stomach or under the tail.
Use tweezers to remove the ticks, pulling straight upwards to make sure the tick is completely removed. Otherwise, mouth parts of the tick may remain imbedded in the animal and infection is still possible.
Ticks need to be on the animal for 12 to 24 hours before they can transmit the infection. Also, you can check with the veterinarian about the use of tick repellants; those based on chemical permetherin are particularly effective.
Equine Lyme disease is not contagious, and one sick animal cannot infect the rest. However, an infected animal is a sign that there are ticks in the area, and that the other animals are at risk as well.