IDEXX research links tick-borne disease exposure, kidney problems in veterinary patients

April 2, 2018

Positive results for B. borgdorferi or E. canis antibodies associated with a higher risk of CKD in dogs later in life.

Shutterstock.comIDEXX Laboratories, makers of the popular IDEXX SNAP 4Dx Plus test to detect exposure to vector-borne diseases, has released internal research connecting exposure to the pathogens causing Lyme disease and ehrlichiosis-the positive “blue dot” result-to kidney problems later in life, even in animals that seemed asymptomatic at the time of the screening.

“To protect our pets and ourselves, we need to stay alert to the risks,” reads an IDEXX white paper detailing the study design and its results. “That means regularly screening pets-including asymptomatic or seemingly healthy ones-to identify exposure to infected ticks.”

How the study was conducted

To conduct the research, investigators at IDEXX performed a retrospective study using results from its patient database. They obtained complete chemistry panel (including SDMA, a biomarker that can signal kidney disease relatively early in the disease process) and urinalysis results logged between July 2015 and January 2017. They then correlated these results with vector-borne disease data gathered between January 2003 and January 2017, according to the white paper.

To be considered “exposed” to infected ticks, a patient had to have at least one positive vector-borne disease test result in its history. Patients were deemed to have chronic kidney disease (CKD) if they showed increased SDMA (>14 μg/dl) and creatinine (>1.5 mg/dl) for at least 25 days and inappropriate urine specific gravity (USG <1.030) in that same period. To establish persistence in these patients, neither SDMA nor creatinine concentrations could return to normal ranges in their available history.

Investigators also correlated these results to the patients' geographic areas-namely, whether or not those areas were endemic for Lyme disease and ehrlichiosis. The patient population included male and female dogs of all breeds from 1 to 25 years old.

What the researchers found

Dogs with antibodies to Borrelia burgdorferi, the Lyme pathogen, were found to have a 43% higher risk of developing CKD. Dogs with antibodies to Ehrlichia species had a 300% higher risk of developing CKD if they lived in Ehrlichia canis-endemic areas (those patients not located in endemic areas did not show increased risk of CKD with Ehrlichia exposure). The results were statistically significant and clinically relevant, IDEXX's white paper states, “indicating that regular monitoring of these seropositive patients is medically necessary.”

“Although the design of this retrospective study does not allow for determination of a causal relationship,” the paper continues in its Conclusions section, “the study supports that dogs who test positive for Lyme disease or Ehrlichia are associated with a statistically significant increased risk of developing CKD in endemic areas. … Consequently, patients of any age that test positive for Lyme disease or Ehrlichia should be considered for comprehensive evaluation. At every annual visit, the patient should receive a physical examination, a complete blood count (CBC), a complete chemistry panel with the IDEXX SDMA Test, and a complete urinalysis to monitor for multisystemic disease.”