Many conditions can affect a dog’s shoulder but injuries, in particular, can be very difficult to diagnose and treat. The most common injury to a dog’s shoulder involves the biceps muscle and tendon. This causes inflammation, swelling, and even tearing of the muscles and tendon fibres which understandably, is painful. The condition is called bicipital bursitis or bicipital tenosynovitis.
How it happens
Bicipital bursitis typically occurs abruptly, usually by blunt trauma when a dog runs into a barrier, or over-flexes the shoulder when the leg gets trapped. It can also happen over time, such as from repetitive exercise that strains the shoulder. We see this often in dogs who are involved in eventing. Obesity puts added pressure on the shoulder joint which increases the chance of injury.
The tricky part of bicipital bursitis is diagnosing it. Many dogs will show a very pronounced limp initially, and then seem to improve, only to limp again after running or jumping or just from playing. The frustrating bit is that when you feel the leg, you are unlikely to feel any changes to the leg and touching the leg does not cause your dog to show pain. If the muscle is affected you might get some sensitivity when feeling over the shoulder, but this is the exception, not the rule.
It takes a skilled veterinarian to test for bicipital bursitis. The shoulder has to be flexed (pulled back), the elbow straightened, and the foot pulled away from the body. This should be done gently as to not cause damage. If a dog shows pain, one can conclude that the biceps muscle and tendon may be hurt. But other conditions, including bone cancer, can also cause pain during this movement. So it is always best that a vet does the exam to look for other possibilities.
• Diagnosis starts with the physical exam to see if the biceps muscle and tendon may be painful. If it is, additional tests are required to determine to extent of the injury, and to exclude other causes of pain in the shoulder.
• X-rays usually do not show the tendon or muscle and in most dogs cannot be used to diagnose the condition. However, in some chronic cases you will start seeing bony changes to the tendon which are visible on X-rays. Special X-ray views are required to look for bicipital bursitis.
• Ultrasound (sonar) with a special machine and well-trained surgeon is one of the most accurate ways to diagnose the condition. One can see the tendon and muscle, evaluate the fibres, and look for swelling or scarring. This examination also allows for samples to be taken.
• MRI can also be used to evaluate the muscle, but costs and availability often make this difficult to do.
Bicipital bursitis must be treated promptly because chronic inflammation can cause permanent tissue damage. Treatment is multifactorial.
- Rest. Exercise restriction to leash walks, very short and very slow, is best, for about 6 weeks.
- Anti-inflammatories. Almost all dogs can benefit from anti-inflammatories. As inflammation is present, and can cause additional damage, managing this with medication is important.
- Additional pain killer. Some dogs are so sore that additional pain killers are needed to help them be more comfortable.
Many dogs, however, will not respond to these treatments and need more advanced treatments. These include:
- An injection of cortisone into the tendon or muscle can help with anti-inflammatory action, although multiple injections may be required and there may be side effects to the cortisone.
- Platelet-rich plasma injection is an excellent way to treat bicipital bursitis. Platelets are injected into the affected area seen on ultrasound which aids healing, much better than rest and oral medication. This is fast becoming the treatment of choice.
This is a very rare form of bicipital bursitis where infection occurs around the tendon. It is mostly due to bite wounds or open wounds that allow infection to enter. The pus will need to be drained, the bacteria analysed and the correct antibiotics prescribed.
In some dogs, none of the above treatments seem to help and as a last resort surgical options are explored. This entails cutting the tendon and allowing it to move into a new position. This results in improvement of pain and most dogs will regain most of their shoulder use. Some may retain a limp, but at least they are pain-free.