FRIDAY, Feb. 22 (HealthDay News) -- Researchers say they have found a way to diagnose and treat osteoarthritis in cats.

The researchers, from the University of Montreal, examined 120 cats and found that 39 had osteoarthritis. The team established methods to evaluate how much arthritis-related pain the cats had and how the disease affected their movement.

Next, the researchers tested the anti-inflammatory drug meloxicam and found that it provided various levels of pain relief depending on dosage levels. Cats that were given the highest dosage of the drug for four weeks continued to have pain relief for five weeks after they stopped receiving the drug, which caused no side effects.

Although meloxicam provided pain relief for cats with osteoarthritis, it did not reduce pain associated with touch, such as petting, according to the study, which was published Feb. 13 in the journal Research in Veterinary Science.

Meloxicam is already used to treat other animals. In April, the European Medicines Agency will consider the use of meloxicam in cats.

More than 80 percent of cats older than 11 years have osteoarthritis, which frequently affects their elbows, backs, hips and joints in the hind limbs, according to lead study author Eric Troncy. Cats with arthritis may become less active, be reluctant to jump and suffer pain when being petted.

"Despite the fact that cats are the most popular pet in North America, nobody had found a way to easily diagnose and treat cat osteoarthritis," Troncy said in a university news release.

Osteoarthritis is the most common form of arthritis in humans.

The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about osteoarthritis.