‘Lameness is a clinical sign of a more severe disorder that results in a disturbance in the gait and the ability to move the body about, typically in response to pain, injury, or abnormal anatomy.’
One problem that can cause lameness in a dog is Bicipital tenosynovitis – inflammation of the tendon and sheath lining of the biceps muscle. It is often the result of many years of small tears or other degenerative changes in the tendon that manifest in middle age, but can also be due to a sudden injury or chronic osteochondritis dissecans of the shoulder joint.
Intermittent or continuous lameness, which is exacerbated by exercise, is a clinical sign of biceps tenosynovitis. On inspection by a vet, there is most likely to be pain upon hyperflexion of the shoulder and extension of the elbow, and direct palpation of the tendon near the shoulder joint may also elicit a painful response.
The biceps tendon attaches on the shoulder blade bone, passes through the shoulder joint and then through a groove in the top of the humerus bone (bicipital groove). The tendon widens into the middle of the biceps muscle and then attaches onto the radius and ulna bones of the forelimb. Contraction of the biceps muscle flexes the elbow and extends the shoulder joint.
Treatment includes exercise restriction, rehabilitation therapy, weight loss and anti-inflammatory medications. In extreme cases, resolution may necessitate surgical treatment. In surgery, the tendon is cut from its attachment to the shoulder blade bone – the tendon will heal onto the top of the humerus bone with time, allowing the muscle to regain its function.
Bicipital tenosynovitis typically occurs in medium-sized or large (typically the Labrador Retriever and Rottweiler), middle-aged or older animals, however small breed dogs can also develop this condition.