New Diagnostic Joint Disease and Pain Tools Could Put Spring Back Into Feline Steps

Cats are known for their crazy antics and acrobatics, but take a look at an older cat and you quickly realize the difficulty these geriatric pets have in performing even the simple tasks they used to do every day-jumping onto a favorite couch or pouncing at a toy mouse. Many of these feline friends suffer more than just the aches and pains of old age. They have a condition called osteoarthritis, a degenerative joint disease that progresses with age and affects about 75 percent of senior cats.

With Morris Animal Foundation pilot-study funding, researchers at the University of Montreal are studying osteoarthritis in a new way, by looking at both the behavior and anatomy of cats with the disease. The scientists are using magnetic resonance imaging (MRI) technology to look at joint damage in the hip lumbar region, elbows and knees of a dozen felines. In animals with the disease, the normal cartilage cushion in the joint breaks down, and the bones rub against each other, often causing bone spurs. Unfortunately, evidence of joint disease doesn't always show up on traditional X-rays, and it can be difficult for even an experienced veterinarian to make the correct diagnosis.

"Underdiagnosis of the disease is leading to undermanagement of osteoarthritis in cats, and also underdevelopment of products dedicated to managing feline osteoarthritis," says Dr. Eric Troncy, professor at the University of Montreal. He says MRI is much more sensitive in showing structural changes in the limbs of cats, which can help veterinarians identify joint disease.

Cats with osteoarthritis often have an altered gait and put more weight on their unaffected limbs. So, researchers are also developing a pain scale and a quality-of-life scale, using quantitative gait analysis and telemetered locomotor activity monitors to record how the disease affects the animal's function levels.

This is the first study aimed at validating both the objective and subjective pain of osteoarthritis, and Dr. Troncy hopes the results will help his team develop an effective treatment for this painful condition. Currently, there is no approved method for alleviating the long-term pain of joint disease in cats, but the results of the study may allow researchers to look at drugs or nonconventional painkillers to help manage the disease.

"This would represent a huge change for cat osteoarthritis management and welfare," says Dr. Troncy. With proper disease management, older cats may find themselves with a bit more spring in their steps.