Supraspinatus Tendinopathy

What is supraspinatus tendinopathy?

You probably have a two-legged friend who has injured her rotator cuff. This shoulder injury is painful and if not treated with proper physical therapy, it can lead to chronic pain, and in some cases a more severe injury or “tear,” requiring surgery.

In the dog, supraspinatus tendinopathy is similar to rotator cuff injury in humans.  The supraspinatus muscle is responsible for extension of the shoulder joint.  Injury to the tendon of the supraspinatus muscle causes inflammation. Tearing of the tendon fibers and the resulting inflammation can lead to mineralization and calcification of the tendon, which are a source of pain and lameness. According to Dr. Wendy Baltzer, DVM, PhD, DACVS, Assistant Professor of Small Animal Surgery at Oregon State University, many different breeds are diagnosed with supraspinatus tendinopathy. While it is an injury that is often seen in canine athletes, it is also seen in show dogs, and family pets.

What are the signs of supraspinatus tendinopathy?

The most common clinical sign of supraspinatus tendinopathy is lameness that gradually worsenswith minimal or moderate activity.  Dr. Baltzer said that supraspinatus tendinopathy is often misdiagnosed and that traditional treatments like NSAIDS and rest may only help the dog temporarily. That’s what happened to Doreen Dysert of Camas, Washington.  Her English Mastiff, Diogenes, began exhibiting signs of foreleg lameness. “We were at a dog show and he began limping while we were in the ring,” said Dysert. “Unfortunately, no one, until we took him to Dr. Baltzer, was able to diagnose his injury. He would rest and his limp would disappear, but it would always return.”  

How is supraspinatus tendinopathy treated?

According to Baltzer, traditional treatments include the surgical removal of the calcification on the tendon. While this treatment may be helpful in some cases, Baltzer’s research is using platelet-rich plasma (PRP) to treat  supraspinatus tendinopathy. PRP is an innovative and non-invasive procedure already approved by the FDA for use in human medicine, and it is used routinely in equine medicine. PRP takes autologous cells --the dogs own cells – and injects them into the site of the injury. Although the exact mechanism of action remains undefined, PRP is thought to contain several different growth factors that aid in the healing of bone and soft tissue. Because a dog’s own cells are used, it is safe and does not produce an adverse reaction. Baltzer’s study has included 12 dogs and she has followed them for up to six years after treatment. According to Baltzer, “The dogs usually only need one treatment. They must rest for eight weeks and then do physical therapy at home, and sometimes I recommend underwater treadmill therapy.” In tracking the dogs in her study, Baltzer has found that the lesions on the tendon heal and the lameness improves. “PRP is about 80 – 90% effective in the dogs I’ve treated,” said Baltzer. Dysert echoes the effectiveness of the PRP treatment. “Diogenes only needed one injection. We followed up with Dr. Baltzer’s recommendation of eight weeks of rest, then PT, and now, Diogenes is one-hundred-percent and back in the show ring.”

Preventing supraspinatus tendinopathy?

Baltzer said that while there is no sure-fire way to prevent supraspinatus tendinopathy, studies have shown that when the injury occurs in canine athletes, a warm-up before an event may be beneficial. Baltzer also cited studies that have shown exercises that improve balance to help dogs who are in agility competitions or similar athletic events. “Dogs that stand on a ball or wobble board will build core muscles and strengthen their ligaments and tendons.”

By taking a few simple steps pet owners can condition their dogs and help prevent injuries. In the process they will spend quality time together and remain active, two things our four-legged friends enjoy the most.