Equine Lyme Disease 101

Lyme disease (borreliosis) is a bacterial infection caused by Borrelia burgdorferi that is transmitted through the bite of infected ticks (especially the deer tick). Borrelia burgdorferi can infect numerous body systems (including skin, muscle, joints, heart, eyes, and nervous system) and affects both humans and animals.

Clinical Signs

Lyme disease is not easy to diagnose. Clinical signs are often very vague and are similar to signs caused by other diseases. Horses with Lyme disease have clinical signs that vary in severity, and many horses will never develop any signs. Signs that have been documented are the following:

Uveitis (eye inflammation)

Swollen Joints

Skin masses or nodules (at the site of the bite)

Neuroborreliosis (a rare form of Lyme disease that can also present fever, muscle wasting, difficulty eating, skin sensitivity, and other neurologic signs)

(Undocumented but possibly signs include one or more of the following: stiffness, lethargy, lameness, change in behavior.)

Prevention

An approved Lyme vaccine for horses is not currently available. If you live in tick-infested areas, strive to reduce exposure of your animals (and yourself) to these parasites by removing brush, leaves, and long grass from your property. Try using insect sprays and repellents and perform full body checks for ticks when you come inside and when you groom your horse. Do your best to discourage deer, birds, and rodents that form a part of the tick life cycle.

*Horses are a dead end host who can not pass the infection to humans or other animals.