BRIGHTON, Colo. (KDVR) — Colorado locals are being warned after a mysterious illness is causing an unusually high amount of cats around Brighton to fall sick or die.

This outbreak comes right after the respiratory disease found in dogs across Colorado. While the illness isn’t known to transfer to cats, felines aren’t in the clear.

The Brighton Police Department tweeted on Wednesday that Brighton Animal Welfare discovered an “unusually high number of sick or deceased cats in the Brighton East Farms neighborhood.”

The department says there isn’t a definitive cause yet, but the Feline Panleukopenia Virus (FPV) was found in the sick cats.

Signs of FPV include generalized depression, loss of appetite, high fever, lethargy, vomiting, severe diarrhea, nasal discharge and dehydration, according to the American Veterinary Medical Association.

The virus is usually passed through urine, stool, nasal secretions or fleas from infected cats.

While it’s not contagious to humans, this can be fatal for young kittens. Older cats have a better chance of survival, but up to 90% of cats may die without supportive care.

Residents have been notified over the past few days by animal welfare officers. It’s recommended that caretakers avoid allowing their cats outside.

Residents caring for stay cats are also advised to avoid leaving out “shared bedding, litter boxes and food sources to avoid cross-contamination,” according to the department.