Osteoarthritis (OA) is a complex condition that involves inflammation and degeneration of one or more joints. It is sometimes referred to as degenerative joint disease (DJD). Cats with OA experience joint pain and inflammation that interfere with daily activities.
OA is diagnosed through a physical examination, palpation (feeling with the fingers to localize pain and determine its intensity), and additional diagnostics, including radiographs (X-rays) and other imaging technology. About 90% of cats over 10 years old experience OA in at least one joint.
What causes OA?
There is no single cause of OA. Many factors influence its development, including:
- Body conformation (how a cat is built)
- Body condition and weight (excess weight and obesity are highly correlated with OA)
- Abnormal joint development (e.g., hip dysplasia, elbow dysplasia, luxating patellas)
- Injury history (e.g., past fracture, ligament damage, muscle injury, joint infection, cartilage damage)
- Orthopedic surgery
- Nutritional history
Most cats with OA experience a combination of these factors as their OA develops and progresses. It is now clear that simple aging is not a cause of OA.
What are the clinical signs of arthritis?
Cats can exhibit many different signs when they have OA, and they do not necessarily demonstrate all the same signs all the time. The most common signs cat owners may notice include:
- Difficulty getting up and down
- Walking stiffly
- Lameness in one or more legs
- Reluctance to go up or down steps
- Reluctance to jump up or down (e.g., onto or off furniture)
- Reluctance to play
- Stiff, swollen, or sore joints
- Reluctance to be touched on some parts of the body
- Unexpected aggression toward other cats or humans
- Hiding more than usual
- House soiling (if they have difficulty getting in and out of the litter box)
- Poor coat condition (because self-grooming becomes difficult)
How is OA treated?
Unfortunately, there is no “magic bullet” treatment for OA. The goal is to manage OA rather than treat it, because OA cannot be cured. OA is a complex disease, so managing it is also complex, and the best results come from combining multiple treatment modalities. Typical multimodal management of OA includes the following:
Nutrition
Normalizing body condition is critical, so your veterinarian may prescribe a specific diet to accomplish this goal. There is a nutrient profile that can support the joints while helping to normalize body weight and condition. It is important to strictly follow the prescribed nutritional program.
Pain Medication
Nonsteroidal anti-inflammatory drugs (NSAIDs) are generally the first treatment used to address the pain of OA. For cats, commonly used drugs include robenacoxib (Onsior®) and meloxicam (Metacam®, Meloxidyl®, Loxicom®, OroCAM®). Your veterinarian will determine if your cat is a good candidate for this class of medication.
In extremely rare circumstances, a corticosteroid anti-inflammatory drug will be prescribed instead of an NSAID. The two classes of medication CANNOT be used together.
Gabapentin is a pain medication that addresses chronic pain differently from NSAIDs or corticosteroids and complements those medications. It addresses the chronic nature of OA pain and is especially helpful when the patient is older and unable to take NSAIDs.
Other Drug Therapies
A newer drug called frunevetmab (Solensia®) is an injection that lasts for a full month. This medication is a species-specific, anti-nerve growth factor (anti-NGF) monoclonal antibody. NGF is elevated in arthritic joints and contributes to pain from OA. Frunevetmab works to block this pain.
Other less commonly used drugs include tramadol and amantadine, but they are less effective unless paired with other drugs mentioned above. Polysulfated glycosaminoglycan (Adequan®) may sometimes be prescribed, although its use in cats is considered off-label. It is important to never reach into your own medicine cabinet when your cat limps or has been diagnosed with OA.
Nutraceuticals
When a nutritional supplement has medicinal effects, it is called a nutraceutical. Many nutraceuticals are available, and many are labeled for use with joint disease. Common products include glucosamine, chondroitin, and omega-3 fatty acids. Ask your veterinarian about the scientific data that supports any nutraceuticals prescribed.
Physical Therapy
Medical acupuncture can provide excellent pain relief for many cats with OA, and other physical medicine disciplines like chiropractic and medical massage may be helpful.
Physical rehabilitation is a discipline that translates physical therapy techniques from human medicine to animal patients. These techniques include therapeutic laser, therapeutic exercise, joint mobilization, and hydrotherapy using an underwater treadmill. Your veterinarian can refer you to a rehabilitation specialist.
Surgery
For the most extreme cases, surgical procedures can alleviate the pain associated with OA. Femoral head ostectomy (FHO) can be done for severe hip dysplasia with good results, as well as joint arthrodesis (fusion) of the carpus (wrist).
Can I do anything else to help my cat be more comfortable?
There are simple ways you can help your cat with comfort and mobility, including:
- Provide soft, padded bedding
- Raise food and water dishes to elbow height
- Provide non-skid floor surfaces
- Provide a ramp or stool/step for getting onto higher surfaces
- Adhere to prescribed feeding and medication recommendations
What is the prognosis for my cat?
With appropriate management, cats with OA can live a normal lifespan. Your veterinarian can provide specific guidance about lifestyle adjustments.
Can feline OA be prevented?
The most effective way to prevent OA is by allowing a cat to grow slowly as a kitten, maintaining a lean body condition throughout growth and into adulthood. Growth abnormalities and injuries cannot always be predicted, so even your best efforts may not be enough to ward off OA in an older cat.
With slow growth, proper nutrition, optimal body condition, and regular exercise, the odds of preventing or at least delaying OA are excellent. Your veterinarian will partner with you to create the best plan for your cat.
