Pet Health Library – Marin Pet Hospital, San Rafael, CA

Lyme Borreliosis – Lyme Disease

Definition: A polysystemic tick transmitted spirochete disease found in the northeastern coastal states, southeast, Midwest, and western states.

Etiologic Agent involved with Lyme Borreliosis is the spirochete, Borrelia burgdorferi

Vector: The vector is the deer tick (Ixodes sammini in the Northeast, Ixodes scapularis in the southeast and Ixodes pacificus in the western states and California). Other species of ticks (including the dog tick) and insects such as horseflies, deerflies, and mosquitoes can carry B. burgdorferi; however, only ticks have been linked with disease transmission. The route of infection is through the bite of an infected tick and requires 48 hours of attachment to the host. Mice are the main reservoirs due to the fact that they maintain the larval and nymph stages. Deer support the adult population but it is thought that they do not become infected by the spirochete. Birds however, may also be important reservoirs because they can transmit ticks and spirochetes over long distances.

Clinical Signs associated with Lyme Borreliosis infection are typically subclinical, but may be septic or immune mediated. These include:

· Sudden joint lameness (usually bilateral and involves the carpus) and evidence of severe pain, depression, fever, inappetence, lethargy, lymphadenopathy, limb shifting due to polyarthritis, acute progressive renal failure and protein losing glomerulonephropathy (especially in Labradors, and Golden Retrievers.), rheumatoid arthritis, meningitis, and myocarditis