Can a Simple Blood Test Improve Canine Liver Disease Diagnosis?

Diagnosing canine liver disease typically involves biopsies, which are costly, invasive, and have the potential for complications. According to the authors of a new study, a simple blood test—derived from one used to detect liver disease in humans—may make early diagnosis of liver disease in dogs simple and straightforward.

For the retrospective study, veterinarians and medical doctors from the University of Edinburgh looked at microRNA-122 (miR-122)—a sensitive and specific biomarker of liver injury in humans and rodents—to determine whether the biomarker might be used to identify liver disease in dogs.

Study Findings

Serum samples from 250 dogs (120 healthy dogs, 100 dogs with nonliver diseases, and 30 dogs with histologically confirmed liver disease) were analyzed. Each sample was measured for miR-122 concentration by polymerase chain reaction (PCR) and then compared with the characteristics of the dogs and their conventional clinical measurements.

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After analyzing the samples, the investigators found no significant differences in miR-122 concentration across breed, sex, age, and weight in healthy dogs. Similarly, there was no difference in miR-122 level between healthy dogs and dogs with nonliver disease. But miR-122 concentration was substantially higher in dogs with confirmed liver disease.

The investigators defined the normal reference interval for calculating miR-122 concentration in healthy dogs, which they now believe allows liver disease to be diagnosed with high sensitivity and specificity.

Future Implications

Current diagnosis of liver disease in dogs is based on biopsy, which can be costly and have the potential for complications. But with the development of a new miR-122 test, the investigators believe that outcomes will improve for dogs with liver disease.

"We have found a specific, sensitive, and noninvasive way to detect liver damage in dogs,” said Richard Mellanby, BSc, BVMS, PhD, DSAM, DECVIM-CA (Internal Medicine), MRCVS, personal chair of comparative medicine at the University of Edinburgh Royal (Dick) School of Veterinary Studies and one of the study authors. "We hope that our test will greatly improve outcomes by allowing vets to make rapid and accurate diagnosis."

The investigators are hoping to launch a test kit with the new miR-122 blood test to help veterinarians better deal with canine liver disease cases in practice.

"I am delighted that the blood test we developed to improve the diagnosis of liver disease in humans can be used to help dogs too,” said James Dear, PhD, FRCPEdin, reader in the University of Edinburgh Centre for Cardiovascular Science and another study author.