Osteoarthritis

Symptoms an owner can spot at home

• Stiffness on rising, especially after rest, that warms out with light movement
• Reluctance to jump on furniture, climb stairs, or play at previous intensity
• In cats: reduced grooming, missed jumps, hesitation at the litter box edge
• Visible muscle loss over the hips, shoulders, or thighs
• Behavioral change—irritability when handled over a joint, withdrawal, sleep disruption

When to see a vet

• Persistent lameness lasting more than a few days, or any sudden non-weight-bearing limb
• Sharp behavioral change suggesting pain that is no longer controlled
• Loss of appetite or sudden weight loss alongside mobility decline
• Inability to rise, posture, or use the litter box / get outside to toilet

What it is

Osteoarthritis (OA) is the chronic, progressive form of joint disease where articular cartilage breaks down, the joint capsule thickens, and new bone (osteophytes) forms at the joint margins. It is the end-stage of nearly every chronic joint problem—developmental disease like hip or elbow dysplasia, post-traumatic injury, or simple age-related wear—which is why it shows up so often in older animals.

Cats develop OA at remarkably high rates: radiographic studies estimate that the majority of cats over ten years old have OA in at least one joint, yet owners report it far less than dogs because cats hide pain by withdrawing rather than limping. The clinical signs are mostly behavioral: missed jumps, reluctance at the litter box, less grooming on the spine.

How vets diagnose it

Diagnosis combines orthopedic exam (range-of-motion, joint effusion, pain on manipulation) with radiographs. Owner-reported behavior is central, especially for cats: validated questionnaires (Feline Musculoskeletal Pain Index, Canine Brief Pain Inventory) give a structured way to track function over time and judge whether a treatment plan is working.

Treatment overview

Editorial overview only—your vet builds the plan. Multimodal management is the standard: weight control, structured low-impact exercise, environmental modification, multi-modal analgesia (NSAID-class drugs and adjuncts in dogs; cat-specific options that avoid feline NSAID toxicity), and rehab. Newer anti-NGF monoclonal antibody therapies have changed the cat picture in particular. Joint nutraceuticals (omega-3 EPA/DHA, glucosamine/chondroitin) have modest but real evidence as adjuncts.

What buyers can do

• Keep the animal at BCS 4–5/9. Weight loss alone has been shown to reduce lameness scores in obese OA-affected dogs in controlled trials.
• Provide a thick orthopedic memory-foam bed; cold and hard surfaces aggravate stiffness on rising.
• Remove jumping triggers—pet stairs or a ramp to the couch, bed, and car; low-sided litter boxes for cats.
• Trade ball-chuckers and pavement jogs for swimming, sniff walks, and balance work to preserve muscle without joint loading.
• Add an omega-3 EPA/DHA fish-oil supplement only on vet advice—dosing matters and quality varies widely.