Lyme disease is a bacterial illness caused by the spirochetal (corkscrew shaped) bacterium Borrelia burgdorferi. It is most commonly transmitted by the bite of infected Ixodes spp ticks, commonly referred to as "deer ticks" or "black legged ticks".

In the United States, Lyme disease is mostly localized to states in the northeastern, mid-Atlantic, and upper north-central regions, and to several counties in northwestern California. In 1999, 16,273 cases of Lyme disease were reported to the Centers for Disease Control and Prevention (CDC).

Equine Lyme Disease: A Review of Experimental Disease Production, Treatment Efficacy, and Vaccine Protection. Lyme disease (LD) is the most important arthropod-borne bacterial infection in the United States. Affecting horses, people, dogs, and cats, LD is caused by the spirochete Borrelia burgdorferi [1-6].

By Sandra L. Bushmich, MS, DVM - Lyme disease is a bacterial illness caused by the spirochetal (corkscrew shaped) bacterium Borrelia burgdorferi. It is most commonly transmitted by the bite of infected Ixodes spp ticks, commonly referred to as "deer ticks" or "black legged ticks".