How Effective Are Pet DNA Tests?

SACRAMENTO (CBS13) — There are DNA testing kits on the market that claim to help you discover the mix of your pet's breed, but do they work?

We bought a few of the kits and asked a geneticist if they're reliable.

When little Alley came into the Sacramento SPCA in October, she was just days old, and no one knew a thing about her history.

"Very small, very weak," said manager Dan Marple. "So we took it in, thinking it was a little boxer puppy."

But Ally wasn't growing fast enough to be a boxer, so staff here, like Marple, began questioning their assessment.

"It's one of those situations where we have to really guess," he said. "So we're looking for characteristics. We're looking for the size of their feet, what their muzzle looks like, the looks, the colors."

Their overflowing curiosity led them to buy a DNA test for Ally. In the meantime, she was adopted by Amy Gaal and her children, who weren't too concerned with the results.

"We knew she'd be cute whatever she was, so yeah, we're going with cute," Gaal said.

Ally's results confirmed she wasn't a boxer, but a mix of American Staffordshire Terrier and Staffordshire Bull Terrier.

Now that she's growing, Marple says the results make sense.

"You're starting to see the features come forth," he said. "The muzzle starting to grow a little bit and the stockiness and the muscle tone."

Marple says curiosity is the biggest reason people want to know the breeds in their mutt, but the tests may also help predict the behavior based on the pet's breeds.

We decided to test a few more mystery mutts from the SPCA: two dogs, both named Minnie, and a cat named Evie.

We bought two different dog tests: Wisdom Panel and DNA My Dog. We found only one brand for cats called DNA My Cat.

The test are relatively easy. They come with brushes to swab the inside of a cat's mouth. You replace them, sent them off and in a few weeks, you get your results.

It's just that simple—or so we thought.

The SPCA's Tracie Popma and Emily Cheng took on the task, which took some skill.

"It looks like we have to do three cheek brushes, and we're supposed to place the brush in between her gums and her teeth," Popma said.

SPCA staff call Evie and exotic long-hair mix with a big bushy tail and a white patch on her chest.

"There are markings of calico in here—she is just a mystery," she said. "So it will be really interesting to see what she comes back with."

Next up is Minnie No. 1. She's a two-month-old black puppy with white patches on her chest and feet, a curled tail and a wrinkly face.

"We're calling her a Chug, which is a Chihuahua mixed with a pug," Popma said. "But if you look at her, she is very tall for a 2-month old puppy. and so the Chihuahua is probably just not in there."

Minnie No. 2 is a gold dog with a coat that looks wiry, but is really soft.

"Her face is so distinguished, but of what breed? Her tail is really bushy, and she's just really short in stature," she said.

All the tests ask that you dry the swabs for up to five minutes before packing them up and shipping them off. Once they're in the mail, the results take up to three weeks.

But how much can you rely on those results?

"No test is probably 100 percent in medicine of veterinary medicine," said University of Pennsylvania School of Veterinary Medicine geneticist Dr. Urs Giger.

He says the tests' accuracy depends on how many breeds are in each company's database. The computers analyzing the DNA have an easier time with simple hybrids, which may explain some key behaviors in your dog.

"Such a test could be very useful if you are looking at puppies and you want to determine whether that is going to be a large breed dog or a small breed dog," he said. "Whether this is going to be a needy dog or a less needy dog, in regard to its behavior."

The results are in.

DNA My Dog says Minnie 1 is a mix of American Staffordshire Terrier, Boxer, Norwegian Elkhound, Poodle, Pug and Staffordshire Bull Terrier.

Wisdom Panel says she is an American Staffordshire Terrier, Boxer, and Pug mix.

DNA My Dog says Minnie 2 is a mix of St. Bernard, Chow Chow, Parson Russell Terrier, Border Terrier and Bloodhound.

Wisdom Panel says she's a Chinese Sharpei, Chow Chow, Cocker Spaniel and Smooth Fox Terrier mix.

Gaal never knew the DNA kits for dogs existed, but she's glad the SPCA went the extra step on her little mutt.

"That probably would have driven me a little crazy to take on this mutt and not know, so I think it's been fun," she said.

DNA My Cat found Evie was a crossbred or random-bred cat without genetic affinity to a specific breed. She has some similarity to the manx breed or ancestors of that breed.

The two different dog tests were between $60 and $65, and the cat test was $119.