When shoulder pain in dogs is present, it can often be difficult to determine the exact joint that is causing a problem. Being able to recognize when your dog has a shoulder issue can be important in relaying the correct information to your veterinarian.
Biceps brachii tenosynovitis is the inflammation of the tendon of the biceps brachii muscle and its sheath. This tendon’s job is to attach to the shoulder blades and cross over the shoulder joint. Important for stabilizing, this tendon of the biceps helps the elbow flex and shoulder extend. Usually caused by acute trauma and repetitive movements, this condition affects athletic dog breeds such as racing greyhounds and agility dogs and medium to large dog breeds such as Labrador Retrievers and Rottweilers. Clinical signs include lameness that comes and goes, pain in the shoulder area, a change in gait, and atrophy of the muscles. Physical exams, radiographs, and an ultrasound can diagnose biceps brachii tenosynovitis. Severity is determined through radiographs that can detect bone spurs in the tendon sheath and mineralization of the tendon. Joint fluid can be tested for possible infection but definitive diagnosing is made through an arthroscopy.
Glenoid fragmentation is the fragmentation of the casual edge of the glenoid which causes chronic shoulder pain and lameness in dogs. More specifically, this injury is located near the glenoid cavity and its surrounding systems. This injury can present itself as asymptomatic (no symptoms) and as an incidental finding when conducting wellness exams. The condition can lead to secondary ossification and traumatic injury if not managed. Clinical signs include shoulder pain, forelimb lameness, and atrophy of the shoulder muscles as it progresses. Typical causes include overuse, trauma, and injury during physical activity. To diagnose, the dog’s history will be looked at to also determine the cause and to rule out elbow problems as well as running standard diagnostic tests and a physical exam.
Polyarthritis is the inflammation and swelling of joints making them painful and swollen that may cause dogs difficulty walking. Immune-mediated Polyarthritis refers to arthritis that’s a direct result of abnormal immune response by the body directed at the joints. This can come from either an auto-immune disorder or infection. Signs include overall joint pain, fever, loss of appetite, swelling of multiple joints, lameness. To diagnose this, a thorough physical examination and a variety of laboratory examinations, including blood and urine tests and urine culture, are common tests used to identify a possible origin of an internal infection.
An Infraspinatus Muscle Contracture is the damage to the infraspinatus muscle and its tendon. The main duties of the infraspinatus muscle is to support the shoulder joint and its flexion and extension so when injured, the damaged muscle and tendon begin to heal with fibrous scar tissue. This limits the healthy movement of the shoulder and its full range of motion. Commonly occurring in active medium to large breeds, this injury largely affects hunting and sporting dogs like the Labrador Retriever. Clinical signs include an episode of sudden lameness and pain caused by trauma or exercise (overuse) which usually subsides within 10-14 days. However, during the healing process, scar-tissue begins to form and cause a decrease in function. An abnormal gait begins to form and pet owners begin to see these symptoms 3 to 4 weeks after the initial injury. Dogs will begin to have one limb shorter than the other due to the tightened muscle with the elbow and foot becoming adducted (held away from the body). Diagnosing can be done through a physical exam where the gait will be observed along with shoulder palpation to feel for atrophy in the affected area. Radiographs help accurately diagnose as well as an ultrasound.
Insect bites in pets are a common problem and while can sometimes be harmless, certain insects can cause serious health complications and pain. It’s important to note the three categories of insects that sting: Vespidae (yellow jackets, and wasps, hornets), Formicidae (i.e. fire ants), and Apidae (i.e. honeybees, African killer bees). While it can take 20 stings from one of these to be lethal in mammals, it can happen quickly if a pet disturbs a hive or colony. Clinical signs that your dog has been bit or stung by an insect include swelling and redness at the site of the bite, hives, swollen face or muzzle, localized pain at the site of the bite (can vary from mild to severe), puncture wound, and itchiness. Dogs experiencing anaphylaxis may have diarrhea, vomiting, weakness, seizures, respiratory distress, cardiovascular arrest, and collapsing. Initial diagnosis is based on the clinical signs being presented. Blood samples might also be taken to help determine an allergic reaction.
Medial Shoulder Instability affects the process of the medial (close to body) aspect of the shoulder joint and it’s soft tissue. This occurs when the medial glenohumeral ligament and the shoulder joint capsule get inflamed and become more lax and frayed. With both large and small breeds being affected, bigger dogs are susceptible through repetitive overuse while smaller breeds experience congenital laxity. Common signs include shoulder pain, chronic lameness that tends to be subtle and recurring, as well as signs of atrophy (muscle loss) at the site. When diagnosing shoulder instability, a physical exam and image diagnosing will take place. Dogs are usually sedated during a physical exam that test shoulder angle movements as muscle tightening due to pain and apprehension can misdiagnose. An ultrasound, CT, and arthroscopy can be used as supplemental diagnostic measures.
Osteoarthritis, also known as Degenerative Joint Disease (DJD), affects both dogs and humans alike and is the most common form of arthritis affecting nearly a quarter of a million dogs worldwide at any given time. It is a progressive, chronic joint condition marked by the weakening of joint cartilage, thickening of the joint capsule, and the forming of new bone around the joint (osteophytosis), both of which contribute to pain and limb dysfunction. The majority of OA in dogs is caused by developmental orthopedic diseases including cranial cruciate ligament disease, hip dysplasia, elbow dysplasia, OCD, and patella (knee cap) dislocation. In a small percentage of dogs, OA develops for no apparent reason and is linked to genetics and age. Bodyweight, obesity, exercise, and diet are all factors that contribute to osteoarthritis. Unfortunately, the damage caused by OA is irreversible but treatment plans help reduce pain and improve quality of life.
Osteochondritis Dissecans (OCD) is a painful abnormality that disrupts the healthy development of bone from cartilage. When OCD happens, a flap of cartilage develops within joints which then causes lameness and joint pain. The most commonly affected joints include the elbow, shoulder, and knee. Dogs with OCD in the shoulder also tend to be male. Factors such as diet, genetics, hormonal imbalance, trauma, growth rate, and joint architecture, can increase the likelihood of developing OCD. Due to its nature, OCD tends to affect larger breeds like Golden Retrievers, Mastiffs, Old English Sheepdogs, Labrador Retrievers, Chow Chows, German Shepherds, Newfoundlands, Bernese Mountain Dogs, Rottweilers, and Standard Poodles. With genetics playing a big role, many vets recommend affected dogs be withheld from breeding. Dogs will start showing signs around 4-7 months of age with many displaying lameness after heavy exercise or long periods of rest. Clinical signs of OCD include limping and lameness in affected legs, vocalization of pain when the affected joint is touched. The affected joint will also be swollen and warm to the touch. Depending on the severity and pain level, dogs may avoid putting any pressure on the affected leg. OCD can affect both legs so determining if one leg is experiencing greater impact can be difficult. Diagnosing this condition primarily includes X-rays, CT scans, or MRIs.
Osteochondrosis is a disorder that affects the development of cartilage and bones in both medium and large-sized dogs that grow quickly. The premature joint cartilage fractures and splits from the underlying bone in this state in which cysts will develop under the cartilage if fluid occupies the room. Cartilage fragments may come loose from the end of a bone and float about in the joint cavity which causes inflammation in the infected joint and may progress to arthritis and cartilage breakdown, restricting joint motion. Signs that a dog may be suffering osteochondrosis include lameness, fluid buildup within the joint, and joint stiffness. To determine the extent of the damage, a veterinarian might take an x-ray but endoscope surgery can also be done to further identify the damage. Another option is a CT scan.
Septic arthritis is a painful disorder caused by the introduction of bacteria or another infectious agent into one or more joints, resulting in debilitating inflammation. Male, large, and giant breed dogs are the most frequently affected, and although septic arthritis may affect dogs of any age, it is most commonly seen in dogs aged 3 to 11 years. Pressure, swelling, and discomfort in one or more joints are all symptoms of septic arthritis. Reduced range of motion in the affected joint(s), as well as fever, lethargy, and a loss of appetite often accompany those prior symptoms. To diagnose, a vet will look at the dog’s complete medical history as well as any injuries that could have caused wounds leading to septic arthritis. They will do a blood test, a physical examination, urinalysis, and a biochemistry profile. Imaging is also used to diagnose septic arthritis in dogs and the vet will test for bacterial infection by taking fluid from a joint which is the most important test during this process
Often seen in canine athletes and working dogs, Supraspinatus Tendonopathy is similar to a rotator cuff injury in humans. The supraspinatus muscle, which is responsible for extension of the shoulder joint, can get inflamed through injury of the tendon. When this happens, the tearing of the tendon fibers and consequent inflammation can lead to mineralization and calcification of the tendon. This results in painful movement and lameness. Causes include long-term repetitive movements such as running, jumping, and turning. Clinical signs include lameness that slowly worsens through physical activity as well as an abnormal gait. Commonly misdiagnosed, this condition can produce scar tissue buildup within the tendon called a supraspinatus bulge. If suspected, diagnosing involves an orthopedic evaluation and imaging. Shoulder movement will be observed for signs of discomfort (flexing and extending) along with other possible pain-causing conditions. Radiographs can help spot any mineralization along with ultrasounds that are used to monitor treatment progression.
Syringohydromyelia is a term used to describe the fluid-filled cavities that develop within the spinal cord that cause an abnormal sensation in affected dogs. Dogs with Syringohydromyelia tend to have an underlying condition called chiari-like malformation (CLM) that results in the brain being too large for the smaller-sized skull. This leads to crowding of the back portion of the skull and eventual obstruction of the flow of cerebrospinal fluid that envelopes the brain and spinal cord. Typical symptoms include an altered sensation at the back of the head and neck with pain, excessive scratching, crying out when jumping/defecating, a sensitivity to touch near the shoulder, ear, neck, and incessant face rubbing. Several breeds can be affected including Cavalier King Charles Spaniel, Chihuahua, Yorkshire Terrier, Maltese, Brussels Griffon and Staffordshire Bull Terrier (unusual, because this is not a toy breed). MRI imaging is typically used to diagnose severity.
Systemic lupus erythematosus (SLE) is an immune-mediated disease in which a dog’s immune system begins to attack its own tissue. Essentially, the dog’s body produces antibodies to antigens that are found in its body systems and tissues. Some breeds have a greater predisposition to SLE such as medium to large dogs that are over five years of age. This includes the Shetland sheepdog, Old English sheepdog, Beagle, German shepherd, Irish setter, Nova Scotia duck tolling retriever, Poodle, Collie, and Afghan hound. Signs of SLE can peak and slow over a period of time, with signs increasing as the disease progresses. These include lameness that moves from limb to limb, lethargy, fever, enlarged spleen, enlarged lymph nodes, ulcers at mucocutaneous joints (lips), muscle pain (or atrophy), skin abnormalities (such as thinning or loss of hair, ulcers, redness). Factors such as genetic, physiologic, and environmental elements can increase SLE development.