Osteoarthritis (OA) is a chronic degenerative disease resulting in changes to the tissues that comprise a joint, such as cartilage, joint capsule, and surrounding bone. OA can develop due to a primary problem with the joint (excess force or abnormal shape) or may develop through wear-and-tear activities of daily life. The primary cause of OA often cannot be identified in cats and the disease is less well understood compared to dogs.
The joints most commonly affected in cats are the hip, stifle (knee), tarsus (ankle), and elbow. Older cats are more likely to be clinically affected by OA. In general practice, OA in cats is an underdiagnosed disease; however, in recent years there is increasing awareness of this condition leading to more frequent diagnosis and better patient care.
Clinical signs of OA in cats are often less obvious than in dogs. Lameness or changes in gait may be observed. Perhaps more commonly, you may note a change in your cat’s activity level or a reluctance to jump up or down.
Diagnosis of OA in cats is made by a combination of physical examination and imaging modalities such as x-rays. Due to their reluctance to be manipulated and held, cats may be challenging to examine; therefore, different types of activity evaluations may be used to assess your cat’s mobility. X-ray changes of OA are apparent in up to 90% of cats, with only an estimated 50% of these having clinical signs of impairment due to joint pain.
A multimodal approach is recommended to treat OA in cats. The basis of this approach is to use a combination of therapies that improve comfort and quality of life. It is important to note that all treatment decisions are made based on individual patients and in discussion with the pet owner and surgeon.
- Weight management. Overweight cats are more likely to show signs of lameness or pain associated with OA. Weight loss through controlled feedings or foods formulated for weight loss may improve your cat’s comfort.
- Nonsteroidal anti-inflammatory drugs While these medications (such as meloxicam and robenacoxib) are effective for treatment of acute pain, potential toxicity deters many veterinarians from long-term use, especially if your cat has kidney disease. Research regarding safety and dosing of these medications for OA in cats is ongoing.
- Adjunctive drug therapy Medications such as gabapentin, amantadine, and tramadol are being increasingly investigated for use in treating chronic pain in cats. There is some evidence to support the use of these medications, but it is not conclusive. Your veterinarian may help you decide if one of these medications could be helpful for your cat.
- Dietary supplements. Supplements such as omega-3-fatty acids, glucosamine and chondroitin are usually well tolerated by cats, but may or may not be helpful in reducing signs of OA.
- Environmental modifications Using steps and ramps and providing soft bedding may improve your cat’s quality of life.
- Physical rehabilitation. This area is just beginning to be investigated in cats and includes different exercises and modalities such as low level laser therapy, therapeutic ultrasound, and massage.
- Surgical techniques. Surgery for OA is less common in cats than dogs, but may be very helpful in certain cases. Surgical options include joint replacement and arthrodesis (fusion of a painful joint).