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15 Elbow Dysplasia




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This article is from the Canine Medical Information FAQ, by Cindy Tittle Moore with numerous contributions by others.

15 Elbow Dysplasia

"Elbow Dysplasia" is a general term that includes any of several
conditions:
1. Osteochondritis Dissecans (OCD)
2. Fragmented Coronoid Process (FCP)
3. Ununited Anconeal Process (UAP)
4. Degenerative Joint Disease (DJD)

Heritability

Evidence that both OCD of the elbows and FCP are heritable in at least
one breed was discussed in "The Inheritance of Osteochondritis
Dissecans and Fragmented Coronoid Process of the Elbow Joint in
Labrador Retrievers" by GA Padgett, UV Mostosky, CW Probst, MW Thomas,
and CF Krecke, published in the Journal of the American Animal
Hospital Association, Vol. 31, pp 327-330. Test breedings showed and
increase in both OCD and FCP when selected for, demonstrating a
genetic potential. However, as normal siblings were also produced,
this condition is _not_ a simple recessive. Most probably it is a
polygenetic trait, similar to Hip Dysplasia, with the attendant
difficulty of removing from the gene pool.

As of this writing, early screening for these conditions in the
breeding stock is strongly advised to eliminate dogs with this
condition. In addition, littermates and close relatives of affected
dogs should be reconsidered as good breeding stock, as they are likely
to carry some of the genes for these conditions.

The paper focused on Labrador Retrievers; however it is quite likely
that as with Hip Dysplasia, Elbow Dysplasia is heritable in a number
of other breeds as well.

Osteochondritis Dessicans

Osteochondrosis dissecans affects dogs of the large, rapidly growing
breeds between the ages of four and twelve months. It usually is found
in the shoulder or elbow joints, but rarely it can affect the hocks or
stifles. It is due to a defect in the cartilage overlying the head of
one of the long bones. A puppy who jumps down stairs might sustain
such an injury. The tendency for cartilage to be easily damaged may be
hereditary. Repeated stress to the joint perpetrates the condition.
The signs are gradual lameness in a young dog of one of the larger
breeds, typically between six to seven months of age.

The lesions primarily affect cartilage and secondarily bone, and can
occur in the elbow, shoulder, hock, and/or stifle, though the elbow is
by far the most common. When the condition is associated with
inflammatory joint changes it is known as OCD.

Pain is present on flexing the joint. X-rays may show fragmentation of
the joint cartilage, or a loose piece of cartilage in the joint.

OCD in the elbow has been proven in the Labrador to be hereditary, but
no such proof has been shown for other forms of OCD or heritability in
other breeds. However, it would be prudent to assume that outside of
traumatic origin, a polygenetic mode of inheritance is at work.

Surgery is indicated to remove the pieces of cartilage, smooth both
the top of the joint and the cartilage to stimulate new growth without
flaps or chips. Recovery and prognosis are generally very good; there
are many cases of dogs who had this surgery and went on to compete in
obedience and agility once completely recovered. However, no matter
how sucessful the surgery, the dog should not be bred if a hereditary
cause is suspected.

Fragmented Coronoid Process

Ununited Anconeal Process

Ununited anconeal process has been known for quite a while in in the
German Shepherd Dog, but can also occur in other breeds (Dobermans
and, increasingly, Golden Retrievers) It is really only one part of a
constellation of problems collectively referred to as elbow dysplasia.

This is a serious condition because it usually results in arthritis
and efforts need to be made to be sure that the dog has enough
exercise to keep fit, but not so much or of the wrong kind that would
make the arthritis more severe. The condition should be handled
surgically by an experienced orthopedic specialist.

It is thought to be genetic, and OFA now certifies dogs based on
X-rays in the belief that its incidence will be reduced this way.

Diagnosis and Registry Any of these conditions must be diagnosed via
radiographic analysis. OFA will certify elbows on dogs 24 months of age or
older. Abnormal elbows are reported as:

Grade I--minimal bone change on the anconeal process
Grade II--additional subchondral bone changes and/or osteophytes
Grade III--well developed degenerative joint disease

Because awareness of these conditions is relatively new, there haven't been
nearly as many assessments for elbow dysplasia as for hip dysplasia.

In their reports, OFA separates ratings into dogs and bitches. Here are some
stats, for the breeds with more than 1000 evalustions:

Rottweiler, 1042 bitches, 38.1% dysplastic--890 dogs, 47.9%
dysplastic
GSD, 2940 bitches, 18.2% dysplastic--2156 dogs, 23.9% dysplastic
Labs, 1398 bitches, 10.4% dysplastic--801 dogs, 15.2% dysplastic

It isn't known why males are consistently higher in percent dysplastic. This
pattern is true for all 16 breeds listed as having more than 75 evaluations
registered.

Besides OFA, GDC will also evaluate and rate elbows.

 

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