While a cheek swab can identify genes associated with specific canine illnesses, it’s often better to avoid relying on such tests. These services, much like human DNA tests, are prone to inaccuracies such as false positives and false negatives.
In a Nature article, two veterinarians and a geneticist recount the story of a 13-year-old pug named Petunia, who experienced difficulty walking and controlling her bowels. Her owners opted for euthanasia after discovering she carried a mutation linked to an incurable neurodegenerative disease—though her symptoms might have stemmed from a more manageable condition.
Many tests rely on early-stage research that hasn’t firmly established a gene’s link to a health issue, or the connection may only apply to certain breeds. For instance, in Petunia’s case, just 1 in 100 dogs with her genetic result are likely to develop the associated disease.
False negatives also pose a significant issue. If a testing company only screens for one of several mutations causing a disorder, the results might misleadingly suggest the dog is free of that condition.
When considering medical tests, whether for yourself or your pet, it’s crucial to ask: How will I respond to a positive result? How will I react to a negative one? Currently, genetic tests for dogs lack the reliability needed to guide significant veterinary health decisions. This mirrors the limitations of consumer-level human genetic tests, meaning dogs aren’t the only ones facing this issue.
