COLORADO — A woman whose dog was killed by a questionable service dog is now taking action against its owner.

Christine Haddow rescued a black, miniature poodle she named Nick. During one walk on a park path in western Colorado, Haddow and Nick encountered a great Dane.

"Massive. He was massive," Haddow recalls.

She tried walking past the big dog and its owner, when all of a sudden, the great Dane lunged toward the miniature poodle.

“The great Dane attacked him from behind and started shaking him like he was a rag doll, and he was screaming,” says Haddow. “I kicked the great Dane in the head, and he dropped Nick."

The injuries were too much for the miniature poodle, who had to be put down.

Haddow later learned the great Dane’s owner claimed the dog was a service dog. The owner of the great Dane showed animal control investigators a service dog certificate she got online. However, the online application never claimed the dog had been trained.

In the U.S., there is no required registration for service dogs. You don't even have to get the dog trained by a professional; you only have to claim the dog performs a specific task that you that you need done.

In this case, the great Dane’s owner tried to blame Haddow, claiming the poodle bit her.

The great Dane’s owner told investor report Jace Larson the same story on the phone, but she declined to comment further.

Haddow decided to fight the other woman's story and took the woman to court.

A judge ordered the owner of the great Dane to pay $2,500, but just a few weeks later, the great Dane’s owner filed for bankruptcy. Haddow hasn’t received a dime of their money.

Haddow worries people can too easily claim their animal is a service dog, or in other cases, an emotional support animal. Airlines have recently cracked down, requiring people to get a doctor's note before an emotional support animal is allowed on a flight.

Having a pet classified as an emotional support animal allows owners to skip the usual pet fee and allows the pet to fly free in the cabin.

"A day doesn't go by that I don't cry for Nick,” Haddow says.

She says she worries what could have happened if she'd encountered the great Dane in a grocery store or restaurant--places service animals are allowed by law.

"My message, and what we've always wanted people to understand, [is] be a responsible pet owner," Haddow says.

