Lyme disease was first recognized in 1975 as a distinct clinical disorder and is currently the most frequently reported vector-borne disease in the United States (CDC 1995). Transmission of the spirochete B. burgdorferi, the causative agent of Lyme disease, occurs by the bite of Ixodes ticks. In the United States, the blacklegged tick, Ixodes scapularis Say affects the greatest number of people for three principal reasons:
- Their geographic distribution coincides in the northeastern United States with the greatest concentration of humans
- Spirochete infection rates are high, often exceeding 25%
- The geographical range of the tick is spreading
Lyme disease is one of many tick-transmitted diseases. The Lyme disease bacterium, Borrelia burgdorferi is carried by the tick between hosts. In dogs, Lyme disease usually produces disease signs characterized by arthritis, though it can less commonly involve heart, nervous system and the kidneys. The skin around the bite, and the lymph nodes also become colonized. The arthritic joints may become swollen and hot, and there may be a fever associated with lethargic attitude and poor appetite. Lameness does not commonly last very long, but may recur in cycles. The glands (lymph nodes) of the dog may also be swollen.
It is important to note that Lyme disease is not found everywhere that ticks are found. Your local veterinary clinic will be able to advise you whether this infection is a concern in your geographic area.