If you and your dog live in a Lyme disease-endemic area of the country, you’re likely aware of its possible symptoms. You also may be aware of a rare, potentially life-threatening form of Lyme disease — Lyme nephritis — in which the bacterium that causes the infection attacks the kidneys. Now, scientists have identified a more insidious threat to your dog’s kidneys.
A new study has connected exposure to Borrelia burgdorferi, the spiral-shaped bacterium that causes Lyme disease, and Ehrlichia canis, the bacterium that causes ehrlichiosis, to increased risk of chronic kidney disease (CKD) in dogs.
A connection, but not a cause, was found
Researchers with IDEXX, a company that provides laboratory services, diagnostic tests and laboratory equipment to veterinary practices, performed the retrospective study using test results from its patient databases. (A retrospective study looks backwards and examines exposures to suspected risk or protective factors in relation to an outcome such as CKD.) They reviewed specific laboratory test results, including complete blood chemistry panels, SDMA test results, urinalyses and positive tick-borne disease tests to identify dogs for the study populations. Investigators also restricted the dog populations to those geographic locations where B. burgdorferi and E. canis are endemic.
Laboratory test results from nearly 467,000 dogs were analyzed and used to calculate the relative risk of CKD. Dogs with a positive Lyme disease antibody test result were found to have a 43 percent higher risk of developing kidney disease than dogs who did not have a positive test result. Dogs with a positive Ehrlichia antibody test result in E. canis-endemic areas were determined to have a 300 percent greater risk of developing CKD.
It’s important to distinguish between what these findings say and don’t say. If you and your dog live in a Lyme disease- or E. canis-endemic area and your dog tests positive for Lyme disease or ehrlichiosis, your dog has an increased risk for developing kidney disease. The study findings do not show that if your dog tests positive for Lyme disease or ehrlichiosis and you live in an endemic area that your dog will eventually develop CKD.
What does this mean for you and your dog?
For starters, you need to be aware of the risks associated with tick exposure and take exposure to these tiny bloodsuckers seriously — for both you and your dog. In other words, you’ll want to be diligent about protecting your dog with a flea-and-tick control product, possibly year-round, depending on where you and your dog live.
You’ll also want to work with your veterinarian to regularly screen your dog — whether symptoms are present or not — to identify exposure to infected ticks. If your dog tests positive for exposure to B. burgdorferi or E. canis, you’ll then want to talk to your veterinarian about routine screening for CKD using the SDMA test. The SDMA test can help identify changes in your dog’s kidneys earlier than blood creatinine levels can and isn’t affected by decreased muscle mass like creatinine. And if your dog should test negative for exposure to infected ticks, that’s great news! It means the preventive measures you’re using are working.
Contact with ticks is becoming harder and harder to avoid. Ticks are hardy and capable of overwintering on wildlife or under leaf litter — even in northern Minnesota — and the areas that they call home are increasing. Ticks are responsible for spreading a variety of diseases in addition to Lyme disease and ehrlichiosis all across the United States, so it’s important to know which ticks and tick-transmitted diseases are present in your area. To learn more about the risk of infection for three tick-borne diseases — Lyme disease, ehrlichiosis and anaplasmosis — check out the 30-day parasite forecast maps at PetDiseaseAlerts.org.