TL;DR: Knobby or enlarged joints are usually signs of chronic conditions like osteoarthritis and are rarely emergencies unless accompanied by sudden pain, heat, or an inability to walk. Providing a photo helps your veterinarian assess the severity and prioritize your dog’s care.
What causes my dog's joints to look enlarged and knobby?
When a dog's joints appear knobby or enlarged, it is often a sign of chronic changes in the bone or soft tissue. The most common cause is Osteoarthritis, where the body creates new bone growth—known as osteophytes—in response to joint instability or long-term wear and tear. In some cases, these 'knobs' may also be caused by hygromas (fluid-filled sacs), localized inflammation, or previous injuries that have healed with significant scar tissue or callus formation.
Is my dog's knobby joint a medical emergency?
- The urgency level for knobby or enlarged joints is generally low because these structural changes typically develop over weeks, months, or years.
- If your dog is still eating, drinking, and able to move around comfortably, you can wait for a routine veterinary appointment.
- Seek prompt veterinary care if the joint is suddenly hot to the touch, if there is an open wound, or if your dog is suddenly unable to bear any weight on the leg.
How does sending a photo help with my dog's triage?
- A clear photo or video allows the vet to see the exact location, size, and nature of the swelling.
- Visuals help determine whether the growth involves the bone or the surrounding soft tissue.
- Comparing the knobby joint to the opposite, healthy limb helps the medical team determine the severity.
- This information allows the team to prioritize your dog's care and provide advice on managing their comfort until they are seen.
Clinical Context (Merck Veterinary Manual)
Enlarged and knobby joints in dogs may indicate various underlying conditions. Polyarthritis can manifest as swollen joints, accompanied by fever, lameness, lethargy, and inappetence; diagnosis involves radiography to assess for joint effusion and erosive bone destruction, alongside joint fluid analysis revealing increased cell counts. Joint trauma, such as cranial cruciate ligament rupture, frequently results from excessive trauma and potentially weakened ligaments due to degeneration, immune-mediated diseases, or conformational defects. Clinical signs include lameness, joint effusion, and reduced range of motion, with lesions commonly affecting the shoulder, elbow, stifle, and hock joints; radiography can identify joint lesions, including flattening of joint surfaces, subchondral bone lucency or sclerosis, osteophytosis, and joint effusion.
Chapter: Orthopedics, Immunology
Source: The Merck Veterinary Manual, 11th Edition (Page 1198)