This is condition that I am seeing more and more in agility dogs. The cause is thought to be repeated contact dismounts and landing from jumps. The clinical signs are a vague front leg lameness that may be mild or moderate and is often intermittent. Response to rest and non-steroidal anti-inflammatory drugs (NSAIDS) is poor. The cause of the problem is calcium deposits that form in the tendon due to repetitive strains.
The shoulder blade (scapula) in the dog runs down the side of the rib cage whereas in people the scapulae run across the back. The other main difference is that in the dog the shoulder is a weight bearing joint.
Shows a schematic representation of the intrinsic muscle of the canine shoulder.
The supraspinatus tendon, which is outside the joint capsule, runs very close to the biceps tendon, which is inside the joint capsule. The calcium deposits increase the size of the supraspinatus tendon, which then impinges on the biceps tendon. This can then cause a reaction in the biceps tendon and within the shoulder joint itself.
As mentioned earlier, the history is usually a mild to moderate shoulder with poor response to rest and NSAIDS. On clinical examination there is usually wasting of the supraspinatus muscle belly. The dog often shows pain when the supraspinatus and/or biceps tendons are pressed. There may be reduced range of motion of the shoulder joint. Diagnosis is by X-ray or CT/MRI scan.
Good positioning for X-ray is essential. Digital X-ray machines produce much sharper images that can then be enlarged.
The initial treatment is with shockwave followed by a rehabilitation programme. Shockwave uses pressure changes and not electrical shock. The probe of the shockwave machine is placed over the area to be treated and between 600-2000 shocks are delivered depending on machine and size of dog. Shockwave works by delivering rapid large changes in pressure. This causes micro fractures in tissues, especially tendons, this then restart the inflammatory and healing processes. Shockwave also dissolves the calcium deposits in the tendon. Normally 3-6 treatments are given at 10-14 day intervals depending on machine and response. Some shockwave machines require the dogs to be sedated as the procedure can be uncomfortable. The machine we use at Physio-vet does not require the dogs to be sedated and is well tolerated.
The use of NSAIDS should be avoided as by using shockwave, we are trying to restart the inflammatory process. NSAIDS would be trying to stop the inflammatory process. For pain relief Pardale V (paracetamol and codeine) or tramadol should be used as these drugs have no effect on the inflammatory process.
During and after the shockwave treatment the dog will need a rehabilitation programme aimed at rebuilding the lost muscle. This would consist initially of passively extending and flexing the shoulder and elbow. The biceps muscle should be gently stretched by flexing the shoulder and extending the elbow.
As the dog progresses through the recovery phase exercises such as High Five Push Ups and Down to Sit should be repeated several times daily.
This condition is under diagnosed and before the advent of shockwave was very difficult to treat.