A woman in Boulder, Colorado allegedly killer her boyfriend's cat by blowing heroin smoke into the animal's face until it overdosed and died.

While police and veterinarians have yet to confirm if heroin was the cause of the death of Muffin, toxicology and necropsy tests will determine if the cat was indeed killed by the illegal drug.

On Thursday night, police responded to a domestic disturbance call at 21 year-old Danielle Blankenship's residence. When police entered the house, they found Muffin the cat unconscious at the bottom of the stairs.

It was breathing, but not moving, Boulder Animal Control Supervisor Janeé Boswell told Denver TV station 9 News. At that point, I picked the cat up to see if it would walk. It took about a step and it went limp and it tumbled over.

The vet clinic called the Poison Control Center to try to find out if there were some specific things they could do to revive the cat. They gave it some IVs, and the cat rallied at one point,  Boulder Police Spokeswoman Kim Kobel told a local FoxNews affiliate. They thought it was going to make it, but then it crashed soon after that and it died about 6:30 last night.

Blankenship's boyfriend, who said he was being abused by the woman at the time, told officers that Blankenship was smoking heroin and blowing the smoke into the cat's face.

Blankenship denied the allegations, saying that she would never hurt her pet or consume heroin.

Our animal control officers have seen poisoning before. They have responded to cases where animals get into household cleaners, bleaches, and things like that. This is an unusual case, if it actually is indeed a drug poisoning like this, a heroin poisoning, Kobel said.

Blankenship was charged with animal cruelty and third-degree assault. She went to jail Thursday, but has posted her $1,500 bond.