Cats with the annoying habit of spraying urine on vertical surfaces are needed at the Cornell University College of Veterinary Medicine for a clinical trial of a new treatment.

The study, which seeks urine-marking cats within driving distance of Ithaca, N.Y., will ask two questions: Are there underlying medical problems in this behavior? And can cats be chemically persuaded to leave their marks by rubbing their cheeks instead of raising their tails?

Cat owners interested in enrolling their pets in the trial are asked to call the Cornell Animal Behavior Clinic at (607) 253-3844. There is a nominal charge of $12 per cat for those that complete the trial. Conducting the study is Diane Frank, D.V.M., a resident in the behavior clinic.

"Let's be clear about urine spraying," said Frank, distinguishing this cat behavior from "normal" urination on horizontal surfaces. "The cat backs up to a vertical surface. Its tail is up and quivering. Then the cat sprays on the vertical surface -- the wall, perhaps, or the furniture."

In cats that have not been "fixed," urine-marking is usually associated with sexual activity, Frank explained. Males may be driving away competing males, or females in heat may advertise their availability. But among neutered cats, the behavior is a bit more mysterious.

"We believe it's used in communication," Frank said. "The cat may be experiencing high-anxiety levels, or perhaps there's some sort of social interaction going on. We do know from studies of semi-feral animals that cats can recognize the odor of their own group members because they spend more time sniffing urine from non-group members."

The Cornell animal behaviorists hope that at least 30 cat owners will take the trouble to complete a questionnaire, then bring their animals to the veterinary college for a medical exam.

X-rays and other tests will look for medical conditions that may aggravate the behavior. Then the owners will be sent home with something that they can spray: a synthetic cat pheromone originally developed in France.

Pheromones are the natural chemicals produced by animals to attract the attention of other animals, particularly others of their own species. Special pheromone glands in cats' cheeks leave a marking scent wherever cats rub their faces. Now the Cornell behaviorists wonder whether substituting the manufactured cheek pheromone for the urine scent wherever the cats have sprayed will encourage cats to leave their marks by rubbing their cheeks on the vertical surfaces -- instead of spraying.

"The alternative treatments for urine-spraying cats are anti-anxiety drugs and environmental changes, but those don't work for all cats," Frank said. "We don't know whether the pheromone strategy will work either. This will be among the first scientific tests of the synthetic pheromone in this country, and the first look anywhere at underlying medical conditions, as far as we know."

The experiment will take cat owners about two months to complete. Results of the study are expected later this year.