Osteochondrosis (OCD)

Osteochondrosis (also known as OCD) is a common, painful disease in dogs. It is characterized by an abnormality in the cartilage-to-bone transformation. As a result, cartilage and bone fragments may break off into the joint space. Osteochondrosis is not a form of arthritis, however, it often leads to arthritis. Larger breeds of dog have a genetic predisposition towards the condition, which results from rapid growth. (The pain from osteochondrosis is similar to the growing pains experienced by adolescents.)

Cartilage is the tissue, normally at the ends of long bones, which contributes to pain-free motion. Osteochondrosis is a congenital defect in normal joint cartilage development that leads to the development of a loose piece or flap of cartilage. This loose piece or flap can give rise to secondary degenerative joint disease. Secondary degenerative joint disease that develops as a result of osteochondrosis, generally occurs early in the dog’s life as opposed to the “wear and tear” arthritis that many dogs experience later in life.

Areas most commonly affected by osteochondrosis include the shoulder, elbow, knee (stifle) and ankle (hock) in young dogs. Osteochondrosis can occur on both sides (bilateral) and may involve several joints. There are several types of osteochondrosis.

Types of osteochondrosis
Conditions that affect the forelimbs include osteochondritis dessicans (OD) of the elbow or shoulder, fragmented coronoid process (FCP), and ununited anconeal process (UAP). When the elbows are affected, these conditions are often referred to as simply elbow dysplasia. Osteochondrosis affecting the hind limbs is less common.
Osteochondritis dissecans (OD) occurs at the surface of a joint when a thickened area of cartilage develops, loosely attached to the underlying bone. This thicker cartilage may crack and cause a flap of cartilage to break away. When this cartilage flap falls into a certain position, your pets discomfort will be minimal but, as it shifts position, pain and joint swelling become acute. OD of the elbow and shoulder usually occurs between four and seven months of age. Breeds most commonly affected include the Labrador, golden retriever and (less frequently) the rottweiler.

Fragmented coronoid process (FCP) of the elbow joint is the most common and severe type of osteochondrosis, affecting a dogs forelimbs. Two bones, the radius and the ulna, run the distance from your pets elbow to wrist. FCP results from either a) abnormal development of the cartilage in an area of the ulna known as the coronoid process, or b) abnormal length of the radius and ulna bones. Between four and six months of age, a small piece of the coronoid process may fragment inside the elbow leading to early onset secondary arthritis. (This usually develops between five and ten months of age.) Retrievers, Labradors, rottweilers and Bernese mountain dogs commonly experience FCP.

Ununited anconeal process (UAP) is a failure of the growth center of the anconeal process (located in your pets elbow joint), to unite properly with the ulna. This fusion should be completed by 16 to 24 weeks of age. The ununited anconeal process is a large piece of bone connected to the ulna by a strand of fibrous tissue. It causes joint instability which may lead to severe secondary degenerative arthritis. UAP disease has been reported in most large breeds, particularly German shepherds and St. Bernards. UAP has also been reported in breeds with short, curved legs such as the basset hound. Your pet may not exhibit signs of UAP until the secondary degenerative joint disease begins to make itself known.

OCD in the stifle (knee) joint
Osteochondrosis in the stifle can be difficult to diagnose, as the lameness is frequently obscure and is often confused with the gait of canine hip dysplasia (CHD).

OCD in the hock (ankle) joint
Affected pets are usually four to five months of age and exhibit slight lameness of the hind limbs. The ankle joints appear straight and swollen and are painful on movement. X-rays show cartilage and bone fragments and bone spurs due to secondary degenerative joint disease.

Signs of possible osteochondrosis (OCD)
Unlike most diseases, the various forms of osteochondrosis (OCD) do not produce immediate, obvious symptoms. There are, however, clues to watch for, particularly if you have a larger breed. These include:
Lameness and pain in the affected joint.
Restricted movement of the affected joint (e.g. paddling effect).
Muscle wasting in the most affected side.
The symptoms of osteochondrosis (OCD) depend on where the problem is located. The dog may try to compensate for lameness by restricting the movement of the affected joint. For example, if the elbow is affected, your pet may swing his/her leg outward in a circular motion to avoid bending the elbow. Although osteochondrosis (OCD) usually affects both sides (i.e. left and right elbows), one leg is often worse than the other. As a result, the dog may take extra weight on the better foreleg, resulting in decreased muscle development in the other foreleg.

Treatments options for your pet with OCD
The treatment for osteochondrosis (OCD) is geared towards inhibiting further breakdown of the hip joint and decreasing the pain your pet is experiencing. Various medical and surgical treatments are available today that can ease your dog’s discomfort and restore mobility. The type of treatment depends upon several factors, such as the age of your dog, the severity of the problem and financial considerations. Management of osteochondrosis (OCD) usually consists of exercise restriction, body weight management and symptomatic pain management with analgesics and anti-inflammatory drugs.
Exercise Control
Restricting the amount and intensity of a puppy’s activity has been shown to reduce the incidence of osteochondrosis (OCD). Flaps of cartilage that have not yet broken away from their underlying bone may heal back if the affected joint use is not too intense or prolonged. All large breed puppies should participate in only regular short walks until they have finished growing; this recommendation is particularly important if the dog already has osteochondrosis. Dogs with osteochondrosis (OCD) should be restricted to the leash and given a maximum of three short (10 – 15 minute) walks per day.

Dietary Restriction
Overfeeding contributes significantly to the development of many orthopedic conditions in dogs, including osteochondrosis (OCD). If your dog has osteochondrosis (OCD), you should discontinue administration of any vitamin or mineral supplements unless specified by your veterinarian. (Consult your veterinarian about an appropriate dog food to give your pet.) Many dogs that develop osteochondrosis (OCD) are the healthiest-looking, largest and fastest growing in their litter; these are the dogs that managed to push out the litter mates from the feeding bowl and are growing too rapidly for the strength of their physical structure. Reduce your dog’s total calorie intake to that recommended by the feed company and your veterinarian.

Analgesic and Anti-inflammatory medications – Ideally, these should only be used for the short term, when necessary to encourage movement. Although your pet may respond quickly to anti-inflammatories, this is usually because they are quelling pain, and not because the condition itself is improving. In most cases these medications act simply as painkillers, and should only be used in addition to lifestyle modifications including weight control and good exercise management.

Commonly prescribed analgesics and anti-inflammatories include acetaminophen and various NSAIDs (non-steroidal, anti-inflammatory drugs).

For mild to moderate osteochondrosis in dogs, your veterinarian may recommend acetaminophen (Tylenol, Panadol, Exdol, etc.) to relieve pain. Since acetaminophen is only a pain reliever and has no anti-inflammatory properties, it can generally be safely combined with anti-inflammatory medications when recommended by a veterinarian.

Too-high doses of acetaminophen can cause liver damage. You should therefore seek a veterinarians advice before administering acetaminophen. Acetaminophen is toxic to cats.

NSAIDs are a type of medication that helps reduce pain and swelling of the joints and decreases stiffness. When taken at a low dose, NSAIDs reduce pain; when taken at a higher dose, NSAIDs can also reduce inflammation. NSAIDs such as ASA (Aspirin, Anacin, etc.) can be purchased without a prescription. NSAIDs do not prevent joint damage and when used over the long-term, may accelerate joint breakdown. Taking more than one NSAID at a time increases the possibility of heartburn and severe side effects such as ulcers and bleeding. (Special buffered ASA is available for dogs.) Many NSAIDs require a prescription such as the newer sub-class of NSAIDs, which do not inhibit proper blood clotting, called Cox 2 Inhibitors (Rimadyl (carprofen), Metacam(meloxicam) and Etogesic (etodolac). Never use Ibuprofen for dogs as it is toxic to a dog’s kidneys.

Cortisone is a corticosteroid that reduces inflammation and swelling. For severe pain and inflammation, veterinarians may inject a corticosteroid, such as cortisone, directly into the affected joint. Cortisone mimics the anti-inflammatory effects of cortisol, which is a hormone naturally produced by the body. Although corticosteroids closely resemble cortisol, they exert a much more powerful anti-inflammatory effect. An injection can provide almost immediate relief for a tender, swollen and inflamed joint.

Pentosan polysulphate (Cartrophen Vet) is an injectable drug is given by injection at weekly intervals, usually on four separate occasions. The drug acts in many different ways, but primarily improves the environment of the joint cartilage. Painkillers are not allowed while pentosan polysulphate is being administered.

Visco-supplementation is the process of injecting a gel-like substance into the joint. This substance lubricates the cartilage, reducing pain and improving flexibility. Visco-supplementation decreases friction within the joint, thus reducing pain and allowing greater mobility. This method of treatment requires ongoing injections as benefits are only temporary. Substances used in visco-supplementation include hyaluronic acid, or HA (Legend, Hylartin and Synacid), and poly-sulfated glycosaminoglycans (PSGAGS) such as Adequan.

Applying heat helps relax aching muscles and temporarily reduces joint pain. (Heat helps to reduce pain and stiffness by relaxing aching muscles and increasing circulation to the area). Applying cold helps to lessen joint pain and swelling (Cold helps numb the area by constricting the blood vessels and blocking nerve impulses in the joint.)

There is some concern that heat may worsen symptoms in an already inflamed joint so monitor your pets reaction carefully following application of heat. Applying ice or cold packs appears to decrease inflammation.

Consult your veterinarian before starting any medicated treatment of your dog. This information is presented for information purposes only and is not a recommendation of treatment.