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Canine Osteochondritis Dissecans
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This is a disease
of cartilage formation, which is an element of elbow dysplasia, but it can
affect other joints such as shoulder and stifles. It tends to affect
rapidly growing large breeds during their growth phase.
Osteochondritis Dissecans
Veterinary & Aquatic Services Department, Drs. Foster
& Smith, Inc.
Osteochondritis dissecans,
commonly known as OCD and osteochondrosis dissecans, is a disease of the
cartilage that affects the joints in a dog’s body. In any joint in the body
two bones come together and movement is allowed between them. Where the
two bones meet, an exceptionally smooth area of cartilage covers their surfaces.
This acts as a cushion and protects the underlying bone. If anything disrupts
this smooth cartilage surface, movement of the joint becomes painful. In
a dog with OCD, this cartilage is damaged or grows abnormally. Instead of
being attached to the bone it covers, it separates or cracks, causing great
pain. In some cases, small pieces of cartilage break off and float free in
the joint. These pieces of cartilage do not die, but rather continue to grow
and increase in size. These are known as joint mice. Approximately 15% of
all dogs will develop OCD. This article will cover the disease and its treatment
and will explore some of the suspected causes.
Who gets OCD?
OCD is primarily a problem in large or giant breed dogs. It has been
reported in small dogs and cats, though it is not very common. It affects
male dogs 2 to 5 times as frequently as females, most likely due to the
males’ larger size and increased stress on the joint. It generally occurs
when the animal is between 4 and 8 months of age, though it can show up
in older dogs. There are several breeds that despite being larger breeds,
have decreased incidences of the disease including the Doberman Pinscher,
Collie, and Siberian Husky.
What are the symptoms of OCD?
The symptoms are lameness in the affected limb. Some dogs have a barely
noticeable limp and others are unable to bear any weight on the leg. The
lameness tends to worsen after periods of exercise and improves after rest.
Seventy four percent of the cases of OCD occur in the shoulder joint, 11%
in the elbow, and 4% in the hock. When it affects the front shoulder, a
shortened forelimb stride may be noted due to reluctance to flex and extend
the shoulder joint. Occasionally, the disease will affect both limbs simultaneously
and the dog may be reluctant to move.
How is OCD diagnosed?
Diagnosis is based on history, physical exam, and radiographs (x-rays).
On physical exam, we notice joint pain. For instance, most healthy dogs
show no resistance when their shoulder joint is fully flexed and extended.
However, if they have an OCD lesion in their shoulder, they may resist shoulder
manipulation and may even cry out in pain when it is attempted. In addition,
this flexion and extension of the shoulder joint may worsen the lameness.
Radiographs of the affected joint are taken to confirm the diagnosis.
The dog is often sedated so that full relaxation of the joint can be obtained.
Several views of the affected joint and the healthy joint on the other side
are taken for comparison. The separations of the cartilage or joint mice
are often identified on radiographs. If the radiographs are not confirmatory
but OCD is still suspected, radiographs may be taken again in 2 to 3 weeks.
What causes the formation of OCD?
Trauma to the joint, hereditary factors, rapid growth, restricted blood
flow to the cartilage, and nutrition contribute to the formation of OCD
lesions.
The cause of OCD is considered to be multifactorial. It is thought that
there are several factors that contribute to the formation of OCD lesions
including trauma to the joint, hereditary factors, rapid growth, restricted
blood flow to the cartilage, and nutrition.
Trauma, whether chronic or acute, may contribute to the formation of
OCD lesions. Injury to the surface cartilage may lead to the separation
of the cartilage from the bone or cause a decrease in blood supply that
leads to cartilage flap formation.
It appears that there is a genetic link between parents and offspring
and the formation of the disease. Certain breeds and genetic lines are
much more likely to develop the disease. Careful screening of parents against
this disease is recommended during the selection of all breeding stock.
The disease usually occurs during periods of rapid growth. Therefore,
it has been suggested that nutrition that creates rapid growth may lead
to the increase in incidence of the disease. It has been recommended that
animals that are susceptible to the disease be fed a diet that is lower
in protein and fat, or that they are fed in a limited manner to allow steady
even growth during the first year of life. This theory may have merits,
but more specific studies need to be done before any general recommendations
can be made.
How is OCD treated?
There are currently two ways to treat OCD; conservative medical treatment
or surgical removal of the lesion. Conservative treatment may be indicated
for dogs that have early mild symptoms of OCD or where a specific lesion
cannot be identified on radiographs. Conservative treatment consists of strict
rest for 4 to 8 weeks. Leash walking is permitted but no running or playing
is allowed. Anti-inflammatories and painkillers such as buffered aspirin
or carprofen (Rimadyl) may be indicated. (Do NOT give your cat aspirin unless
prescribed by your veterinarian.) In addition, the use of glucosamine/chondroitin
products has been suggested, yet there are no current studies that confirm
their beneficial use in this particular disease. Conservative treatment
may be difficult in young active puppies who may still need to undergo surgery,
if the symptoms do not improve.
Surgery is indicated in animals that show severe symptoms, in cases
where large lesions are identified on radiographs, or when conservative
treatments fail. The surgery is very straightforward. The affected joint
is opened and the offending flap, defect, or joint mouse is removed. There
is a very high success rate for surgery and most animals recover fully without
any further problems.
How is OCD prevented?
Prevention consists of careful selective breeding that avoids the breeding
of animals with a history of OCD. Young large and giant breed dogs should
not undergo strenuous activity, particularly jumping activities. Housing
on hard concrete surfaces has been linked to increased OCD lesions in pigs
and may also contribute to problems in the dog. Providing a good balanced
diet that promotes even sustained growth is also recommended. There are currently
many large breed puppy foods on the market made specifically to help reduce
the incidence of bone formation problems. While there has been no evidence
that these diets actually reduce the incidence of this disease as compared
to other commercial puppy foods, future studies might support their use.
Summary
OCD is a cartilage problem that affects young large and giant breed
dogs. It is due to several factors including genetics, trauma, rapid growth,
and nutrition. Treatment is either conservative including strict rest, or
surgical removal of the damaged cartilage. Prevention is aimed at good genetic
selection, reduced activity, and careful feeding.
References and Further Reading
Brinker, W.; Piermattei, DL; Flo, GL. Handbook of Small Animal Orthopedics
and Fracture Treatment. W.B. Saunders Co. Philadelphia, PA; 1983.
Compendium. 'Osteochondritis Dissecans of the Canine Tarsal Joint,'
Compendium; July 1994.
Harari, J. The Veterinary Clinics of North America, 'Osteochondrosis.'
W.B. Saunders Co. Philadelphia, PA; 1998.
Copyright
© 1997-2007, Foster & Smith, Inc. All Rights Reserved.
C 2006 Drs. Foster and Smith, Inc.
Reprinted as a courtesy and with permission from PetEducation.com (
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reprinted with kind permission from Josie Pitterle Article Reprint Coordinator
Drs. Foster and Smith
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The above information is simply informational.
It's intent is not to replace the advice of a veterinarian nor to assist
you in making a diagnosis of your pet. Please consult with your own veterinarian
for confirmation of any diagnosis. Your pets life may depend on it.