Dissecans is commonly referred to as OCD. It 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
and 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 treatments 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 joints. 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, 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. 74% 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
Diagnosis is based
on history, physical exam and radiographs (x-rays). On
physical examination we notice joint pain. For instance,
most healthy dogs show no resistance when their shoulder
joint is fully 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 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?
The cause of OCD
is considered to be multi factored. 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.
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
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 the disease is recommended
during the selection of all breeding stock.
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
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 of 4 to 8 weeks. Leash walking is permitted
but no running or playing is allowed. Anti-inflammatory and
painkillers may be indicated. In addition, the use of
glucosamine/chondroitin products has been suggested yet
there is not current studies that confirm their beneficial
use in this particular disease. Conservative treatment may
be difficult in young active puppies that may still need to
undergo surgery if the symptoms don't improve.
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
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 also been linked to increased OCD lesions in
pigs and may also contribute to problems in the dog.
Providing a well balanced diet that promotes even sustained
growth is also recommended.