Feline osteoarthritis (OA), also known as degenerative joint disease, is a chronic, progressive disorder characterised by the degradation of articular cartilage, subchondral bone remodelling, synovitis and pain. Historically the condition is underdiagnosed in cats due to their unique presentation of pain and mobility issues. Thanks to recent advancements in diagnostic imaging techniques and increased awareness among vets, the condition has been brought into sharper focus. This article reviews the pathophysiology, risk factors, clinical manifestations, diagnostic approaches and pain management strategies for feline OA.
Pathophysiology and risk factors
Osteoarthritis is a multifactorial condition arising from an imbalance in anabolic and catabolic processes within the joint. The degradation of cartilage leads to the exposure of subchondral bone, which becomes sclerotic and often develops osteophytes. These changes result in inflammation, chronic pain and reduced joint function.
Key risk factors for feline OA include the following.
- Age: ageing is a primary factor. Cumulative joint wear and tear along with a natural decline in reparative mechanisms contribute to disease development
- Obesity: excessive body weight increases mechanical stress on joints and promotes systemic inflammation, exacerbating the progression of the disease
- Joint trauma: previous injuries, such as fractures or luxations, can lead to secondary OA
- Developmental abnormalities: congenital conditions, such as hip dysplasia and patellar luxation, predispose cats to early onset OA
- Genetic factors: certain breeds, such as Maine Coons and Bengals, show a predisposition to joint abnormalities and degenerative changes
Clinical signs and diagnosis
Behavioural and lifestyle changes are often the first indicators of the disease and the first clinical signs that owners report
Unlike dogs, cats with OA rarely exhibit overt lameness. If lameness is apparent, it can be very subtle and difficult to spot. Behavioural and lifestyle changes are often the first indicators of the disease and the first clinical signs that owners report. These include:
- Reluctance to jump up in the house or outside
- Reduced jumping height
- Difficulty grooming, leading to an unkempt appearance
- Changes in litter box usage, including inappropriate elimination
- Altered demeanour, such as irritability or withdrawal
- Sudden resentment to being stroked or touched
- Difficulty navigating stairs or other vertical structures
Physical examination
It is important to note that the tendency of cats to mask pain necessitates thorough observation of behavioural cues in the consult room. Palpation may reveal joint thickening and swelling, pain, effusion, decreased range of motion or crepitus. Lameness, a change in posture and difficulty getting up may also be noted.
Diagnostic imaging
Radiographs remain the cornerstone of diagnosis. They can reveal joint space narrowing, osteophyte formation and subchondral sclerosis. Advanced imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) provide greater detail and are valuable in complex or refractory cases.
Validated pain assessment tools
These tools provide a standardised approach to assessing pain severity, enabling vets to tailor treatment plans effectively.
Commonly used tools include the Feline Musculoskeletal Pain Index (FMPI), a caregiver-reported questionnaire designed to evaluate mobility and behaviour changes associated with chronic pain. The Client Specific Outcome Measures (CSOM) tool can be used for objectively assessing pain and tracking treatment outcomes. It allows caregivers to monitor specific activities meaningful to the individual cat. Additionally, the Glasgow Feline Composite Measure Pain Scale (CMPS-Feline) is a validated tool for assessing acute pain, though it can be adapted for chronic conditions like OA. These tools enhance the ability to monitor treatment efficacy over time, improving the quality of life for affected cats.
These tools enhance the ability to monitor treatment efficacy over time, improving the quality of life for affected cats
Pain management strategies
Effective management of feline OA requires a multimodal approach, combining pharmacological interventions, non-pharmacological therapies and environmental modifications. The primary goals are to alleviate pain, improve mobility and enhance the cat’s quality of life.
Pharmacological options
Non-steroidal anti-inflammatory drugs
Non-steroidal anti-inflammatory drugs (NSAIDs) such as meloxicam and robenacoxib are pivotal in reducing inflammation and providing analgesia. Long-term use is feasible with careful monitoring of renal function and gastrointestinal health. Regular bloodwork is essential to minimise adverse effects. It is important to discuss with owners their role in monitoring their cats while using NSAIDs so that they are aware of their responsibilities.
Analgesics
Gabapentin is effective for neuropathic pain, and is commonly used alongside NSAIDs. Sedation and ataxia are potential side effects but are generally transient.
Tramadol may be beneficial in select cases, although is inconsistently absorbed in cats. Palatability remains a challenge.
Adjunctive medications
Amantadine is an NMDA receptor antagonist that is effective for chronic pain and can be used in combination with NSAIDs or gabapentin.
Buprenorphine is a partial opioid agonist that is valuable for acute exacerbations but is less practical for chronic use due to cost and administration challenges.
Disease-modifying osteoarthritis drugs
Polysulfated glycosaminoglycan (PSGAG) injections slow cartilage breakdown and support joint repair.
Nutraceuticals – omega-3 fatty acids, glucosamine and chondroitin sulfate – may provide adjunctive benefits by reducing inflammation and supporting cartilage health.
Non-pharmacological interventions
Weight management
Achieving an ideal body condition score is critical. Obesity can exacerbate joint stress and systemic inflammation, accelerating disease progression. Tailored weight-loss programmes combining dietary restriction and controlled exercise are highly effective ways of keeping cats at a healthy weight.
Environmental modifications
Adapting the living environment can significantly enhance a cat’s comfort and mobility. Recommendations include:
- Providing ramps or steps to facilitate access to elevated areas
- Using low-sided litter boxes for easier entry
- Offering orthopaedic bedding to reduce pressure on joints
Physical rehabilitation
Physical therapy techniques such as passive range-of-motion exercises, massage and hydrotherapy can improve joint mobility and muscle strength. Collaboration with a veterinary rehabilitation therapist is recommended.
Complementary therapies
Studies suggest that acupuncture stimulates endorphin release, reduces inflammation and improves circulation in arthritic joints.
Low-level laser therapy has shown promise in reducing pain and promoting tissue healing.
Surgical options
Surgery for osteoarthritis in cats is typically only considered when conservative treatments […] no longer provide sufficient relief
Surgery for osteoarthritis in cats is typically only considered when the conservative treatments mentioned above no longer provide sufficient relief. One common surgical option is joint fusion, particularly for the hip or elbow joints. This can help stabilise the joint and alleviate pain by removing movement in the affected area. Another option is total joint replacement, although this is more commonly performed in dogs. It can, however, be an option for cats in certain cases, especially for hip arthritis.
In some situations, arthroscopy or arthrotomy may be used to remove damaged tissue or to clean up the joint, which can reduce inflammation and improve function. Surgical intervention is generally reserved for advanced cases of OA when pain management becomes challenging, and the goal is to improve the cat’s mobility and quality of life. As with any surgery, careful consideration and a frank discussion with the owner is essential to determine the best course of action based on the severity of the condition and the cat’s overall health.
Monitoring and long-term care
OA is a lifelong condition requiring continuous management and periodic reassessment. Follow-up appointments should include pain assessments, physical examinations and adjustments to the treatment plan based on clinical progress.
Monitoring strategies
- Regular pain evaluations using validated scales
- Routine bloodwork to ensure the safety of long-term pharmacological treatments
- Imaging studies to monitor disease progression or assess changes in clinical status
Client education
Empowering cat owners with knowledge about OA is crucial. Provide clear instructions on medication administration, recognising pain signs and implementing environmental modifications. Encouraging compliance and proactive communication will improve outcomes.
Emerging treatments
Ongoing research and interdisciplinary collaboration are essential to refine diagnostic tools, develop innovative treatments and enhance the overall standard of care for feline OA patients
Emerging therapies hold promise for transforming feline OA management. Monoclonal antibodies targeting nerve growth factor (NGF), such as frunevetmab, have demonstrated significant efficacy in controlling pain. Regenerative medicine approaches, including stem cell therapy and platelet-rich plasma, are also under investigation and may offer new avenues for long-term disease modification.
Ongoing research and interdisciplinary collaboration are essential to refine diagnostic tools, develop innovative treatments and enhance the overall standard of care for feline OA patients.
Conclusion
Feline osteoarthritis is a prevalent but often underdiagnosed condition that profoundly impacts the quality of life in affected cats. A comprehensive understanding of its pathophysiology, clinical presentation and management options is critical for effective intervention. By employing a multimodal approach and prioritising patient-specific care, vets can mitigate the disease’s progression and significantly improve the well-being of their feline patients.
