Lyme disease (borreliosis) is an infectious, tick-borne disease first recognized in dogs in 1984. It is caused by Borrelia burgdorferi, a type of bacteria called a ' spirochete'. The common deer tick Ixodes scapularis (formerly called Ixodes dammini) is the primary carrier of B. burgdorferi in the Northeast and upper Midwest. The tick Ixodes pacificus is the primary carrier in the West.

Lyme disease can affect individual pets differently. Some animals may display no symptoms. Other animals may develop fever, loss of appetite, painful joints, lethargy, and vomiting. If left untreated, the spirochete may damage the eyes, heart, kidneys, and nervous system.

To protect your dog against lyme disease, avoid tick-infested areas (especially areas with tall grass and brush), vaccinate, and use tick control products such as Frontline Plus or Frontline Spray.