Tick Exposure and Kidney Disease Risk in Dogs

With another higher-than-average tick season looming, veterinarians should be preparing for the inevitable onslaught of tick-related veterinary visits. Even with knowledge of the dangers of tickborne illnesses, pet owners continue to put off annual screenings. But a new study aims to help change that narrative.

A retrospective study, conducted by IDEXX researchers, set out to determine whether exposure to tickborne disease is associated with an increased risk for chronic kidney disease (CKD) in dogs in endemic areas.

Research Method

A total of 846,626 canine chemistry and urinalysis samples were obtained from the IDEXX Reference Laboratories database between July 13, 2015 and January 17, 2017. Dogs ranged in age from 1 to 25; all breeds and genders were represented.

Of the samples evaluated, patients exposed to infected ticks were defined as having a minimum of 1 positive vector-borne disease test result in their available history. CKD was defined as concurrent increased SDMA (symmetric dimethylarginine; >14 μg/dL) and creatinine (>1.5 mg/dL) for a minimum of 25 days with inappropriate urine specific (<1.030) gravity during that time.

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Patient results were analyzed according to geographies known for transmission of both Borrelia burgdorferi (the causative agent of Lyme disease) and Ehrlichia canis (the causative agent of ehrlichiosis), and then CKD risk was calculated.

Results and Implications

An association was identified between dogs with positive Lyme disease or Ehrlichia test results and an increased risk for CKD in endemic areas.

The investigators found that dogs with 1 vector-borne disease had a 300% increased risk of developing kidney disease when Erlichia antibodies were present in dogs living in E canis—endemic areas, and a 43% increased risk of developing kidney disease when Borrelia antibodies were present.

These results reinforce the need to screen dogs annually to identify exposure to infected ticks and various tickborne diseases.

From a public health perspective, Jennifer Ogeer, DVM, MSS, MBA, MA, medical affairs marketing manager for IDEXX Laboratories, Inc., says screening dogs annually is critical to help people better understand potential tick-related risks in their area, as well as help veterinarians provide better care for their pets.

“By doing that, we’re in a much better position as veterinarians to identify if these dogs are going to develop kidney disease,” Dr. Ogeer said. “Then we’re able to have a discussion with those pet owners to build compliance around managing and monitoring that disease earlier, potentially improve outcome, and maybe even life expectancy for these dogs."

The investigators acknowledged several limitations in the study that should be explored further. The study design indicated a statistically significant association between tickborne disease and CKD; it did not allow inference of a causal relationship. In addition the data did not identify the time of tick exposure or onset of tickborne disease, nor did it evaluate clinical presentation, treatment, or patient outcome.