Dog Bone & Joint Health

Jumping, running, fetching, digging... all specialties of dogs and puppies because of their nervous and musculoskeletal systems. Learn more about their anatomy, function, and diseases of bones, joints, muscles, ligaments, tendons, and nervous system.

When abnormal stress is placed upon the skeletal system, fractures or breaks of the bones may occur. All the possible fracture types and the proper corrections of fractures are described by difficult terminology. Basically, we refer to fractures not only based on the name of the bone broken but also on the characteristics of the break itself.
Types of fractures

There are four commonly seen fractures in the dog: closed, compound, epiphyseal (growth plate), and greenstick (hairline). These first three types can be further characterized by whether they are simple fractures in which the bone breaks into only 2 or 3 pieces, or comminuted where the bone shatters into many pieces.

Closed Fractures: Closed fractures are those in which the skin is not broken. The bone is fractured, but the overlying skin is intact.

Compound Fractures: Compound fractures are breaks in which the broken bone protrudes through the skin, and is exposed to the outside. Compound fractures are risky in that the bones can be contaminated with dirt and debris, resulting in an infection.

Epiphyseal Fractures: Epiphyseal fractures are commonly seen in young, growing dogs. In animals less than one year of age, there are soft areas near the ends of each long bone where growth takes place. These soft areas are referred to as growth plates or epiphyseal plates. Because these are areas of growth, they are rich in immature non-calcified cells that form a soft, spongy area of the bone. These growth plates are more easily fractured because they are the weakest part of the bone. The distal ends of the femur (thigh bone) and humerus (upper front leg) seem to be particularly susceptible to this fracture.

Greenstick Fractures: Greenstick fractures are small cracks within the bone which leave the bone basically intact, but cracked. In other words, the bone is not completely broken.
What are the symptoms and risks of fractures?

The symptoms and risks depend on what area and to what extent the bone is fractured. Fractures involving a joint are the most serious. A broken back may displace the spinal cord and cause complete paralysis. All fractures, however, are serious and should be treated at once. When a bone within a leg is broken, the dog will usually hold the entire leg off the ground. No weight is placed on the paw. With a sprain or lesser injury, it may use the leg somewhat, but walk with a limp.
What is the management?

Just as in human medicine, splints, casts, pins, steel plates, and screws can be used to realign the bone and allow healing. The treatment depends on the type of fracture, age of the dog, and which bone is broken. Compound fractures in which the risk of infection is high are treated differently than closed fractures. Growing puppies may heal in as little as five weeks, and because of their size they put less weight on the bone. Therefore, a fracture in a young puppy may be treated with a cast but the same fracture may need to be 'pinned' in a geriatric (senior) dog in which healing may take twelve weeks or more. Hairline fractures may only require rest, while surgical intervention will usually be needed in more severe fractures. Careful evaluation by a veterinarian will determine the proper treatment.

A dog's spine is made up of numerous small bones called vertebrae. These extend from the base of the skull all the way to the end of the tail. The vertebrae are interconnected by flexible discs of cartilage - the intervertebral discs. These discs provide cushioning between each bone and permit the neck, spine, and tail to bend, allowing changes in position and posture. Above the discs and running through the bony vertebrae is the spinal cord, which is made up of a mass of nerve fibers that run back and forth between the brain and the rest of the body.
What is diskospondylitis?

Diskospondylitis (also spelled 'discospondylitis') is a bacterial or fungal infection of the vertebrae and the intervertebral discs in dogs. The resulting swelling, inflammation and bone deformities seen in diskospondylitis put pressure or compression on the spinal cord which runs through the vertebrae. The disease is termed "spondylitis" when only the vertebrae are involved. The disease should not be confused with 'spondylosis,' which is a non-infectious fusion or degeneration of the vertebrae.
What causes diskospondylitis?

Diskospondylitis seems to occur most commonly in areas of the country that have a problem with plant awns (e.g., grass seeds, fox tails). It is thought that bacteria or fungi on the awns enter the blood system when the awns pierce the skin. Bacterial endocarditis, urinary tract infections, or dental disease/extractions may be another means by which bacteria enter the bloodstream and infect the vertebrae. Brucella canis has also been found to cause the disease in dogs.
What are the symptoms of diskospondylitis?

Common symptoms of this disease include weight loss, lack of appetite, depression, fever, and back pain. Dogs with this disease are generally reluctant to run or jump.
How is diskospondylitis diagnosed?

Diagnosis of diskospondylitis can be difficult. Blood tests, urinalysis, radiographs (x-rays), and spinal taps may be necessary to diagnose the disease. Cultures of blood and urine are often performed to help isolate the cause and choose the appropriate treatment. Myelography may be indicated to determine the exact location of spinal compression. Surgery may be needed to reduce the compression on the spinal cord.
How is diskospondylitis treated?

Treatment is based on finding the causative agent - fungal or bacterial. Because bone infections are difficult to treat, therapy lasts at least six weeks and may continue for six months or more. Taking radiographs at regular intervals during treatment helps monitor the progress. The lesions seen early in the disease should resolve with treatment.

Clinical improvement (lessening of symptoms) usually occurs within two weeks of starting treatment. Pain medication may be needed early in treatment. Exercise restriction may help decrease the pain also.

The prognosis depends on the ability to eliminate the infection and on how much nerve damage resulted from the spinal compression.