Genetic testing in human and animal medicine has been used for some time, and shows great promise, when used judiciously. For example, genotyping the avian influenza virus and other pathogens has helped animal and human health officials understand the spread of pathogens so that measures can be implemented to prevent or mitigate such spread.
As reported by Greg Cima, “[f]aster, cheaper genome sequencing is helping public health researchers identify the risks of drug resistance and medical treatment failure . . . The sequences also may help federal investigators find outbreak sources, by geographic location and species, as well as guide vaccine and antimicrobial development.” Finding risks in a flood of genetic data, JAVMAnews Issues, Aug. 1, 2016. .
According to Dr. Jerold Bell, a small animal practitioner and adjunct professor at the Tufts University Cummings School of Veterinary Medicine, “[c]ompanies are using diagnostics to determine what breeds exist in a mixed-breed dog . . . Some companies take it one step further and also tests for genes controlling body conformation and known disease-causing mutations.” M.S, Filippo, Genetic testing for pets quickly catching up to its human counterpart, AVMA press release, 8/8/2016.
Diagnostic test results are rarely dispositive, and the reliability of the results can be influenced by many factors, including, but not limited to: sample collection; quality control and quality assurance of test reagents; method and proficiency of testing; and interpretation of test results. Even tests performed by USDA-APHIS-approved laboratories that are part of the National Animal Health Laboratory Network, using reference materials and proficiency tests produced at the National Veterinary Services Laboratory that are accredited to international standards, must be interpreted by knowledgeable clinicians.
As a large animal veterinarian, when I received laboratory results from state or private laboratories that did not seem consistent with my patient’s clinical signs, I would consult with the laboratory director and other officials to discuss those inconsistencies. Sometimes, additional testing was warranted. In some cases, the final results were never definitive.
As the Director, Division of Animal Health, New Jersey Department of Agriculture I was responsible for the oversight of the only animal health diagnostic laboratory in the State, and for interpreting laboratory results related to regulated and reportable diseases. That analysis started with the laboratory test results, and where the results appeared inconsistent with the clinical signs of the tested animal, an in depth review of the testing process from sample collection to results ensued.
Based on this extensive background and understanding of testing, I am concerned about the inappropriate use of certain genetic tests to refute the pedigree registration status of purebred dogs. As several courts have held, genetic testing is currently not dispositive of pedigree registration status. See, e.g., Sandra Shines v. Furry Babies Stratford Square, Inc., No. 13-3592, slip op. at 9 (Ill. 18th Jud. Cir. Jan. 22, 2014) (finding DNA test results unreliable to support plaintiff’s claim that the cocker spaniel in dispute was a mixed breed).
Mars Veterinary, a business unit of Mars Petcare that sells a DNA genetic test called Wisdom Panel® warns that the test is not “intended to be used in any judicial proceedings” and further suggests that “[i]f questions arise as to a purebred dog’s pedigree and breed ancestry, parentage testing through the AKC is the appropriate course of action. For this evaluation, the documented sire and/or dam are examined to ensure they were the genetic contributors to the dog in question. If they are confirmed as the parents, their pedigree (and breed) is conferred onto the puppy.” See Wisdom Panel® Terms and Conditions.
The purebred status of dogs is based on documentation confirming each dog’s lineage, required by the relevant breed canine breed registries—not the results of DNA testing. Similarly, ancestry DNA testing in humans could not be used to nullify the citizen status of a third-generation U.S. citizen, no matter what their genetic makeup reveals.
The proper use of genetic testing is reflected in AVMA’s new policy on “Inherited Disorders in Responsible Breeding of Companion Animals” which “supports research in genetic and inherited disorders to better educate the profession and breeders on identifying and minimizing inherited disorders in companion animal breeding programs.” K. Burns, AVMA passes policy on responsible pet breeding, JAVMAnews, Feb. 15, 2017.
Undoubtedly, genetic testing will be used as a increasingly important tool for pathogen tracking, disease control purposes, to help guide responsible dog breeders and to help identify the genetic make-up of mixed breed dogs, with unknown pedigree.