Canine Physiotherapy

Osteoarthritis, also referred to as Degenerative Joint Disease (DJD), is a progressively worsening inflammation of the joint caused by the deterioration of cartilage. In a healthy joint, cartilage acts as a cushion to allow the joint to move smoothly through its full range of motion. In cases of osteoarthritis, this cartilage cushion begins to break down because of factors such as age, injury, repetitive stress, or disease. The loss of this protective cushion results in pain, inflammation, decreased range of motion, and the development of bone spurs. While any joint in the body can develop osteoarthritis, the condition most commonly affects the limbs and lower spine.

The word “dysplasia” means “abnormality of development”. The elbow is a complex joint because it involves the articulation of three bones. If the three bones do not fit together absolutely perfectly as a result of abnormal development, the consequence is abnormal concentration of forces on a specific region of the elbow joint.

Forms of primary cartilage disease may also constitute abnormal development of the elbow joint resulting in significant clinical consequences. The term ‘developmental elbow diseases’ may be a more descriptive nomenclature for this condition since most people will have heard of ‘dysplasia’ only in reference to the hip joint. Elbow dysplasia and hip dysplasia both mean that the conformation of the joint is abnormal. In hip dysplasia, the end result of the abnormality in all dogs will be osteoarthritis accompanied by pain and reduced range of motion. Treatment mostly consists of management of the osteoarthritis or joint replacement. In elbow dysplasia, the forces concentrated on specific areas of the joint will not only result in osteoarthritis (as happens with hip dysplasia) but also in discrete pathological entities like fractures within the joint that may need to be managed separately and alongside the osteoarthritis.

The cranial cruciate ligament (CrCL) in dogs is the same as the “anterior” cruciate ligament (ACL) in humans. It is a band of tough fibrous tissue that attaches the femur (thigh bone) to the tibia (shin bone), preventing the tibia from shifting forward relative to the femur. It also helps to prevent the stifle (knee) joint from over-extending or rotating.

n the vast majority of dogs, the cranial cruciate ligament (CrCL) ruptures as a result of long-term degeneration, whereby the fibres within the ligament weaken over time. We do not know the precise cause of this, but genetic factors are probably most important, with certain breeds being predisposed (including Labradors, Rottweilers, Boxers, West Highland White Terriers and Newfoundlands). Supporting evidence for a genetic cause was primarily obtained by assessment of family lines, coupled with the knowledge that many animals will rupture the CrCL in both knees, often relatively early in life. Other factors such as obesity, individual conformation, hormonal imbalance and certain inflammatory conditions of the joint may also play a role.

The patella (kneecap) is a small bone that is positioned immediately above the tendon of insertion of the quadriceps muscle group onto the top of the tibia (shin). The patella acts as a fulcrum during normal extension of the knee joint. It glides up and down within a groove that forms the front of the knee joint. In some dogs, the patella luxates (dislocates) out of this normal groove. The consequence of this luxation is an inability to properly extend the knee joint. As well as the lameness caused by the mechanical deficiency of the affected knee, there are varying degrees of pain and osteoarthritis.

Patellar luxation is a common condition. It affects mostly dogs (although cats can also be affected) and is more common in smaller dogs (although dogs of all sizes can be affected). The age at onset of clinical signs is variable. Most animals start to show signs as puppies or young adults, although onset of signs in mature dogs is also common. Animals with a “bow-legged” stance are more likely to be affected by patellar luxation. A characteristic “skipping” lameness is often seen, where animals will limp for a few steps and then quickly return to normal. Some animals will limp continuously and some dogs affected by patellar luxation in both knees will have a stiff, awkward gait with knees that do not extend properly.

The long bones of dogs and cats are almost identical to the bones of the legs and arms of people. Dogs and cats can break these bones due to vehicular trauma, fights with other animals, and some sporting injuries, to name a few causes.

A bone can break in many ways and we call these breaks “fractures.” To make it easier to plan for therapy, veterinary surgeons classify fractures into several categories.

Incomplete: a fracture that is more like a bend in the bone; the bone may only be broken partway around the circumference of the bone; most commonly seen in young animals.

Complete: the bone is broken through its full circumference and two or more bone fragments are created.

Typically, severe lameness is noted and the affected limb is obvious. Most pets with fractured limbs will hold up the affected limb. Some pets are able to bear some weight on the limb, depending on the location and nature of the break.

Two of the most common spinal injuries in dogs are fibrocartilaginous embolism (FCE) and acute non-progressive nucleus pulposus extrusion. Both conditions cause temporary paralysis and weakness, particularly in the hind legs. The disorders are mainly seen in large breed dogs but can occur in miniature schnauzers and shelties. Both disorders are treated through physical therapy.

Fibrocartilaginous embolism occurs when a blood vessel that feeds the spinal cord becomes blocked by a piece of cartilage that originates from the intervertebral disc. Similar to a stroke, this results in a lack of blood flow to the spinal cord, causing it to malfunction.

During an acute non-progressive nucleus pulposus extrusion, a portion of healthy intervertebral disc suddenly collides with the spinal cord at a high velocity, causing bruising and sometimes bleeding within the spinal cord.

Dogs with these spinal injuries often have been exercising, playing, or have had some mild trauma such as a fall. They may initially yelp and cry out in pain when the incident occurs but show no signs of pain afterward. The onset of signs is sudden, and many are not able to walk immediately after the incident. In some cases, only one hind leg may be affected, or one hind leg may appear worse than the other.