What is shoulder instability?

Medial shoulder instabilities in dogs are similar to a rotator cuff injury in human’s. These types of injuries typically present with your dog presenting with minor limping, to almost non-weight bearing. Patient’s with medial shoulder instabilities will typically show unwillingness to make tight turns.

There are several different forms of shoulder instability. Some dogs experience a low-grade repetitive sprain injury to the shoulder ligaments or a strain injury to the muscles of the rotator cuff. Affected animals are often middle-aged, athletic, large breed dogs. Lameness in affected dogs is often worse after exercise. Dogs affected by high-grade sprains and strains of the shoulder joint may experience an obvious permanent limp.

How is shoulder instability diagnosed in dogs?

Diagnosis of shoulder instability is made using a physical examination test that is usually performed under sedation or general anesthesia. Your dog’s orthopedic clinician will also perform radiographs to check for the presence of osteoarthritis and one of our veterinarians may also take imaging of your dog’s shoulder joints using MRI which can be helpful when assessing dogs with suspected strain injuries. All of the above procedures require either sedation or general anesthesia. Following advanced diagnostic imaging, your dog may undergo arthroscopy of the shoulder joint. Arthroscopy is a keyhole surgical procedure that uses a fibre-optic camera inserted into the shoulder joint to allow visual examination of the associated joint tissues and will provide an optimum opportunity for your orthopedic surgeon to evaluate any abnormalities further.

How is shoulder instability treated in dogs?

Treatment of shoulder instability depends on the grade of sprain and strain, and the degree of instability. Low-grade injuries are often treated non-surgically with anti-inflammatory medication, exercise modification, physiotherapy and hydrotherapy.

Additionally, we use a custom hobble system in low grade to middle grade injuries. A Hobble Vest used for a medial shoulder instability prevents the forelimbs from abducting or moving away from the patient’s midline.

Shoulder fusion (arthrodesis): In animals affected by the most severe problems affecting the shoulder including severe instability, dislocation (luxation), articular fractures and arthritis, arthrodesis may be the best option. This is called a “salvage” surgery because it is used as a last resort where other techniques to save the joint would have a poor probability of success.

Prosthetic stabilization: This surgical technique for shoulder stabilization is modeled on the techniques used for the management of rotator cuff tears in humans.

These injuries are typically treated in conjunction with restricted activity, arthroscopy, and laser therapy. The use of professional rehabilitation has proved to significantly improve patient recovery with shoulder instability. A home care physiotherapy plan will be designed specifically to your dog’s needs by one of our canine physical rehabilitation practitioners at the Animal Clinic of Billings and Animal Surgery Clinic and outpatient hydrotherapy appointments on our underwater treadmill can be made through our rehabilitation service.

How will I know if my dog or cat has Medial Shoulder Instability (MSI)?

Dogs and cats with shoulder joint instability often present with a history of chronic lameness, which is often subtle and intermittent but can be severe and continuous. These patients tend to respond poorly to therapy with nonsteroidal anti-inflammatories alone. Physical signs of atrophy (wastage) of the shoulder muscles of the affected limb, as well as pain at shoulder joint manipulation are common.