According to a research study published in the Journal of the American Veterinary Medical Association (JAVMA) cats over 12 years old have a 90 per cent chance of developing DJD — a condition that occurs when cartilage on the ends of the bones is damaged.
This change is irreversible and veterinarians often see this problem in senior cats (older than eight years). The pain caused by these changes in affected joints may have a severe impact on a cat's quality of life.
Dr. Kira Penney, a clinical associate at the Western College of Veterinary Medicine (WCVM), says owners often miss the signs of DJD in their animals.
"Owners don't recognize the signs of pain in cats because they are so good at hiding it. They just tend to scrunch up in a little ball and sleep more," says Penney, who is certified as a canine rehabilitation therapist (CCRT) and is awaiting her certification in veterinary acupuncture.
In reality, these cats are showing signs that they're reluctant to do their normal, day-to-day activities such as jumping up and down off furniture. Penney finds that once she asks questions about how their pets' behaviours have changed over the years, owners begin to recognize that pain may be the real cause of their cats' inactivity.
It's important to let your veterinarian know if you have concerns about DJD in your pet. While radiographs can be helpful, being on the lookout for behaviour changes in your cat is the first line of defense.
Dr. Elisabeth Snead, a board-certified small animal internal medicine specialist at the WCVM, has some suggestions.
Signs of DJD may be as subtle as a decrease in appetite or in regular grooming because the animal is in pain. As well, some cats may avoid using the litterbox if it is painful for them to reach the box or step in to it.
Fortunately, owners can do some things to help their cat have a better quality of life while living with DJD.
"Keeping them lean – that's probably the biggest … preventive measure they can take," says Snead. "If you are carrying extra weight on your joints, that's much more concussive injury every time you take a step, let alone if you run down the stairs and you're the flabby cat with a belly."
Snead says many cats are simply fed too many calories. When a cat is spayed or neutered, their caloric requirements decrease significantly. Unfortunately, most people don't adjust the amount of food they are feeding, and as a result, feline obesity is a significant problem. Obesity rates in cats are between 35 and 60 per cent depending on the region in which their owners live.
"There are lots of reasons to keep your cat trim, but arthritis is certainly an important one, and diabetes is [another] really important one," says Snead.
Your veterinarian may prescribe medications for pain control or recommend supplements for joint health such as glucosamine or chondroitin.
"Knowing what medications are and are not appropriate in a cat is really important. We all take Tylenol when we have aches and pains, but it's deadly to a cat. You can also have a cat in acute kidney failure pretty quickly with the use or overdosing of other types of commonly-used pain medications such as ibuprofen or Aspirin," says Snead.
"You definitely have to be careful, and I've definitely seen owners with good intentions make those mistakes, unfortunately."
Not only are cats sensitive to many medications, each cat is an individual and your veterinarian will have to take into account the entire animal when considering choices for treatment.
"That's the issue with cats and arthritis: they're just not as straightforward as dogs with arthritis because of their high incidence of kidney disease," says Snead.
While it might sound counter-intuitive, exercise is a good thing for cats diagnosed with DJD. Cartilage changes can't be reversed, but gentle exercise can help maintain muscle strength and prevent stiffness. For example, incorporating a tricky treat ball for meals may help encourage movement in a reluctant pet.
Rehabilitation is an option that Penney feels is underused.
"We don't see as many cats in rehab as maybe we should. When I was in Halifax, I had a couple [cats] that were coming in for underwater treadmill [exercise], laser therapy and acupuncture and they did great. I think it would be nice if more owners were aware that it was an option for cats." says Penney.
"As part of the overall plan for any older animal, rehabilitation is nice. Even if you don't think there is a problem, it's still good to give you some ideas how to keep them moving or keep them comfortable …."
There are also numerous ways to help modify the environment for your cat. Ramps or steps may help your pet get to its favourite windowsill, or a heated bed might provide some comfort to sore joints.
"Lots of it is environmental enrichment and that is the limit of the imagination — the sky's the limit," says Snead.
"I definitely think degenerative joint disease is under-treated in cats because it's unappreciated by owners and under-diagnosed by veterinarians. So can we all do a better job for our feline family members? Yeah, we can."
Gwen Roy of Edmonton, Alta., is a second-year veterinary student at the Western College of Veterinary Medicine (WCVM) and a wildlife biologist.