Many tick-borne diseases-including anaplasmosis, ehrlichiosis, Rocky Mountain spotted fever, babesiosis, bartonellosis, and mycoplasmosis-can be found in areas enzootic for Lyme disease. Sensitive and specific in-house tests, such as the IDEXX SNAP-4Dx (www.idexx.com), have shown that many dogs are seropositive for Lyme disease and other tick-borne diseases. A positive Lyme test may just be a marker for tick and wildlife contact and the patient may have been exposed to a variety of organisms. Many of these organisms can create a carrier state with no apparent clinical signs, and when there are clinical signs, the diseases have similar presentations. The author recommends an annual SNAP-4Dx test for dogs in her area. Although she may not treat animals with a positive Lyme test, she monitors them with urinalyses and checks for proteinuria with the ERD HealthScreen urine test (www.heska.com). Sick dogs are challenging, and many diagnostic tests should be done, including antibody titers and lymph node aspirates, in addition to checking for proteinuria.

COMMENTARY: This article reminds us that ticks commonly transmit infections other than Lyme disease. More practitioners are screening dogs for tick-borne diseases, which can lead to the question, "What to do with a positive result?" The author describes diagnostic testing available to work up both healthy and sick dogs, but there are some inconsistencies and confusion in distinguishing exposure, infection, and true disease. Practitioners reviewing this article are advised to consult other sources of information to help establish diagnostic and treatment protocols. -- Craig Datz, DVM, Diplomate ABVP

Coinfections in Lyme endemic areas. Littman MP. Proc NAVC 2008, p 704.