Joint Swelling in Dogs

Joint swelling is uncommon in dogs, but is associated with many conditions ranging from mild to potentially life-threatening. Swollen joints are always cause for concern, and an affected dog requires prompt medical attention.

If a dog is unable to bear weight on a limb, presents with extreme lethargy, fever, or pain when the joint is touched, these indicate an emergency and immediate veterinary assistance is required.

Joint swelling typically occurs as a result of fluid such as blood, septic fluid, or joint fluid (synovial fluid) building up within a joint’s space. In some cases, tumors or abnormalities of the bone or cartilage cause firm swelling of the joint.

Damage to the structures of the joint through traumatic injury can occasionally cause joint swelling, however these changes are typically mild. Most cases of acute traumatic joint injury, such as rupture of the cranial cruciate ligament, do not show significant joint swelling, despite having serious consequences for joint function and long-term health.

A dog which has recently suffered a physical injury may have swelling in only one joint. This may result in acute swelling, caused by bleeding, inflammation, or septic fluid buildup in the joint. These cases may result in more sudden, severe, and noticeable swelling.

Chronic swelling is more gradual, and can be initially difficult to notice. Conditions such as polyarthritis can lead to joints swelling over a period of weeks. Chronic swelling is often accompanied by joint pain, and difficulty moving- symptoms which appear intermittently, and increase over time.

The age of onset also increases suspicion of certain conditions over others. Older dogs are more prone to osteoarthritis or tumors, such as osteosarcoma, while younger dogs are more likely to have developmental abnormalities such as osteochondrosis.

If multiple joints are swollen simultaneously, that implies a systemic illness. In such cases a dog will often also present with lethargy and decreased appetite.

A physical examination is often sufficient to recognize the symptom. Diagnostics to identify the underlying cause include:

• Bloodwork
• Urinalysis
• Diagnostic imaging, such as X-rays or ultrasound
• Joint fluid analysis (arthrocentesis)
• Testing for specific infectious diseases
• Biopsy of the joint capsule

Treatment depends on the underlying cause. In some cases, symptomatic therapy is sufficient, such as giving the dog anti-inflammatory medication, analgesics, or simply rest and time to recover. Antibiotics may be used in cases of infection, or radiation and chemotherapy in cases of cancer. Surgical intervention is often required to treat many conditions, including elbow dysplasia, osteochondrosis, septic arthritis, and kneecap displacement (among others).

Over-the-counter pain medication should not be used to treat the symptoms without veterinary prescription, as they mask the symptoms of the condition without treating the cause. Veterinary pain medication should not be substituted by human pain medication, as it may be toxic for a dog.

Injuries, such as hematomas (bruises), near a joint may swell, and may also be mistaken for joint swelling due to proximity.