Equine Lyme Disease

Borrelia burgdorferi infection in horses is common in some areas of North America, but the incidence of clinical disease has not been determined, which makes Lyme disease controversial in the horse. Progress is being made case by case in defining the several clinical presentations of Lyme disease in adult horses. Current serologic tests are very sensitive and specific for detecting either infection (previous or concurrent) or exposure but may not distinguish between them. Treatment protocols are available for Lyme disease in horses; however, the ability of those protocols to eliminate the organism remains questionable. Currently, minocycline is being attempted in some presumed Lyme cases as an improved alternative to doxycycline and oxytetracycline. Vaccination, like many aspects of Lyme disease, remains controversial, although the canine-approved vaccines have the potential to prevent infection based upon vaccine studies in ponies and other animals.