I wrote about the pitfalls of doggy DNA tests a few months ago — how they might cause people to panic about the potential that their dog is carrying a marker for a genetic disease or lead people to make unhelpful assumptions about the dog’s behavior.
I just saw a review in Wired examining three DNA testing services. So I have to chime in again.
These tests are not very accurate. They basically compare parts of your dog’s genome with all of the other dogs in the database and make guesses based on finding snippets that match. Each service has different dogs in the database, so there will be different matches.
The caveats about deciding what training method to use or panicking about diseases that your dog doesn’t have still hold. Even so, it can be fun to explore your dog’s genetic makeup. But buyer beware.
Like much data collection that exploits human subjects, the fun wrapper is hiding business motives. The parent company of the Wisdom Panel, for example, is a gigantic dog food manufacturer. One that happens to sell overpriced (poor quality) foods targeted at specific breeds. If your dog is found to have a significant proportion of Breed X, guess what? Little ads will start stalking you, trying to get you to buy food tailored to that breed — a concept which is absurd.

On the other hand, Embark is a spinoff of Cornell’s canine genomics initiative, according to Wired. They look at many more disease markers and are building a database that could someday contribute to research on all sorts of doggy health issues. Cool. It’s also the only one that claims to help you find your dog’s relatives. That’s also the most expensive one, of course.
For me, the bottom line is why you’re doing it. The test itself can be mildly uncomfortable for the dog, and the dog certainly doesn’t care about the results. If it’s all in fun, great. But if you’re trying to discover some deep truth about your dog, you’re better off just hanging out with him and getting to know him better. Instead, donate the $70 — $200 you’d spend on the test to your local shelter.