TL;DR: A grinding sensation in a cat's knee, known as crepitus, is typically a sign of chronic arthritis or a luxating patella and is usually not an emergency. Schedule a veterinary appointment for a mobility assessment unless your cat is in acute pain or cannot walk.
What does it mean if I feel a grinding sensation in my cat's knee?
A grinding or crunching sensation in the joint, medically known as crepitus, typically occurs when cartilage has worn down, causing bone to rub against bone or other tissues. In cats, this is most frequently associated with feline osteoarthritis or a luxating patella, where the kneecap slides out of its groove. While it may feel alarming, it is usually a sign of chronic change rather than an acute injury.
Is a grinding sensation in my cat's knee considered a veterinary emergency?
- The urgency level for a grinding sensation alone is Low, as this is generally a chronic condition that requires a scheduled appointment rather than an emergency visit.
- Seek immediate care if your cat is suddenly unable to bear weight or is vocalizing in pain.
- Contact a vet sooner if the joint is hot to the touch.
- Most cases can wait for a regular consultation to discuss long-term joint support and pain management.
How does providing a photo or video help with my cat's joint triage?
- A video captures a gait analysis of your cat walking, jumping, or transitioning from sitting to standing.
- Visuals help a professional see how the grinding sensation specifically impacts your cat's mobility.
- Video helps determine if the issue is mechanical, such as a slipping kneecap, or purely degenerative before you step into the clinic.
Clinical Context (Merck Veterinary Manual)
Degenerative joint disease, though more common in dogs, can occur in cats and may manifest as lameness, joint swelling, muscle atrophy, pericapsular fibrosis, and crepitation. Radiographic findings include joint effusion, periarticular soft-tissue swelling, osteophytosis, and subchondral sclerosis, with CT scans useful for determining the severity of bony changes; commonly affected joints are the tarsus, stifle, and phalangeal joints. A multimodal treatment plan is recommended, incorporating medical treatments such as NSAIDs, chondroprotectants, and potentially opioids, alongside nonmedical modalities. Radiography reveals joint effusion and signs of degenerative joint disease in chronic injuries.
Chapter: Orthopedics, Musculoskeletal
Source: The Merck Veterinary Manual, 11th Edition (Page 1197)