Is your cat sick, or just not happy?

COLUMBUS, Ohio, Jan. 4 (UPI) -- If your cat refuses to eat and vomits excessively, it may not be sick -- just unhappy, U.S. animal researchers say.

When cats in a study at Ohio State University experienced "unusual external events," like a new caretaker or different feeding schedule, healthy ones were just as likely as chronically ill ones to exhibit behaviors indicating illness, LiveScience.com reported Monday.

"For veterinary clinicians, when you have a cat that's not eating, is not using the litter box or has stuff coming up out of its mouth, the quality of the environment is another cause that needs to be addressed in coming up with a diagnosis," said study researcher Tony Buffington, an OSU professor of veterinary clinical sciences.

Changes in the cats' routines included stopping contact with usual caretakers and changes in feeding and play schedules.

Healthy cats in the study showed the same amount of sickness behaviors in response to disruptive events as the sick cats, researchers said, and in both groups the risk of acting sick over changes in routine tripled from when everything stayed the same.