Authorities are looking for a man who killed a dog in Wellington.

On Monday night, between 10:30 and 11:10 p.m., a man attacked two dogs in a fenced-off yard off of Sixth Street, nearby a McDonald’s, according to the Larimer County Sheriff’s Office.

“One of the dogs died during the attack, and the other was seriously injured but is expected to recover,” the sheriff’s office said in a news release.

The dog’s owner, Yadhira Morales is offering a $1,000 reward for information leading to the arrest of a suspect, according to a GoFundMe page.

The dogs, Jax and Diesel, were in a fenced yard when a man stabbed both animals from outside the yard. Jax, Morales’ PTSD emotional support dog, died in the attack, according to GFM. Diesel suffered injuries and was treated by a veterinarian. Money raised by the page will help pay medical and cremation bills. It will also fund the reward.

As of Thursday afternoon, the page had raised $1,560 out of a goal of $3,000, according to GFM.

The assailant is described as a white man, about 6 feet tall who was wearing a dark T-shirt and light colored pants, the police said. He is believed to be connected to a motorcycle with an Arkansas license plate.

Anyone with information on the incident, or on a possible suspect, is asked to call the sheriff’s office at 970-498-5509.