Muscle and Bone Disorders in Dogs

Muscular and skeletal disorders are common in dogs; causing pain and limiting mobility for your pet. These disorders tend to effect your canine’s body movement and function and stem from a problem within a body system often referred to as the musculoskeletal system. Bones, muscles, and joints are all physical components that make up this system, which helps to support weight, facilitate movement, and protect vital organs. In fact, the musculoskeletal system also does a lot more. Everything from chewing and swallowing, breathing, urinating, and defecating are responses facilitated by muscle contractions and movement that arise from this system. In the following article, we will discuss some of the common disorders of the musculoskeletal system as well as symptoms that let you know it’s time for your pet to see the veterinarian.

Limping is often the first sign noticed by a pet owner that something is wrong. Limping can be graded by severity ranging from mild to unable to bear weight on an effected limb. Dogs may feel pain and show discomfort when attempting to touch a painful or sore area. There are many causes for limping, decreased function, and pain that range from minor soft injuries to more severe causes including ligament tears and even cancer.

Soft Tissue Injuries

When we picture a routine day for a dog, what do we think of? Running, jumping, playing, chasing balls, frisbees, and squirrels. Even for more sedentary dogs, jumping on and off the couch and running up and down the stairs are just part of their normal routine. Unfortunately, sometimes during normal play injuries to muscles and other soft tissues can occur. Just like with their human companions, muscle pulls, sprains, and tears can occur. Often these cases are milder forms of limping where dogs can still bear weight but have a noticeable limp. Usually only a single limb is effected at one time.

Ligament Tears

Just like with humans, dogs have Cruciate Ligaments. These provide stabilization to the lower bones of their rear legs. When a human tears their “ACL” this is what their doctor is referring to. In canines, we have modified the term slightly to “CCL” but the injuries are very similar in nature. Dogs with cruciate tears tend to hold a single rear leg flexed at an angle, often times unable to bear weight on the effected limb or walk with a severe limp. 50% of dogs who tear a ligament in one hind limb will tear the other leg’s cruciate ligament sometime in the future.

Hip Dysplasia and Osteoarthritis

Hip Dysplasia and resulting arthritis are unfortunately common conditions in our canine companions. Dogs affected by this disorder tend to have difficulty getting up and walking stiff, especially in the morning or after prolonged rest. Hip Dysplasia is a congenital/genetic disorder, meaning an abnormal conformation or anatomical defect passed down from their parents results in arthritic changes and disease. Despite the disease being genetic, symptoms often appear to gradually worsen with age and may not be apparent for several years after birth. Dogs can develop arthritis unrelated to Hip Dysplasia in any joint in their body.

Inter-vertebral Disc Disease

IVDD is condition caused by compression of the spine, resulting in inflammation and pressure on the spinal cord. IVDD can occur in the neck, thoracic, or lumbar spine. This results in the delay or inability of nerves to send signals to and from the brain. As a result, effected dogs can have symptoms ranging from delayed replacement of their paws (when picked up) to lack of pain and even complete paralysis. Where the condition occurs along the spinal cord will determine which limbs are affected. IVDD can range in severity from milder forms to emergency/critical situations depending on the degree of compression to the cord. When loss of deep pain and motor are present, it is critical to get your dog to the hospital as quickly as possible, as surgical intervention is required immediately to relieve this compression. With milder cases, extremely strict rest and medication may be enough to get the inflammation to subside.

Cancer

Cancer of muscles, bones, and in joint spaces is possible. Osteosarcoma, or cancer of the bone does occur in dogs. The most common sites are near the “wrists” of a dog’s front leg or the “knee” in the rear although this cancer can form in any bone. Dogs with osteosarcoma may have no clinical signs until they suddenly take a normal step and appear to break their leg. Radiographs are recommended to diagnose as the area of the bone affected will tend to appear “moth eaten” on an x-ray.

Summary

The above diseases represent just a few of the more common injuries and conditions seen in the muscular and skeletal system of dogs. Other causes including infections (tick borne disease), traumas, other congenital disease, and more can also cause similar but often subtly different signs. Because bones, muscles, and joints comprise such a vital and diverse role in the body, there are many causes of pain and limping. If you suspect your dog has a condition or injury which has limited their movement, we recommend scheduling an appointment with a member of our veterinary team who will perform a complete physical examination and recommend testing or treatment options that will help diagnose and treat your dog. With proper management, many of these conditions can be cured or controlled, getting your dog running, playing, and chasing the frisbee or tennis ball once more.

Jeffrey Stupine, V.M.D

Medical Director, World of Animals