Hip Dysplasia in South Africa
-Dr. Mark Rubinsohn
Hip Dysplasia (CHD) is a developmental disease seen most commonly in larger,
well fed faster growing dogs. It causes a painful hip joint
with persistent and unrelenting lameness. It is usually present in both
hips, but the degree of severity may differ in the two hips. Although adverse
environmental factors can influence hip joint development, CHD is essentially
a disease with a high degree of heritability. It is a condition that may
require medical treatment and often radical medical treatment. Eventually
it may require Euthanasia of the dog.
From as early as 4 or 5 months the
pup may show signs in difficulty of getting up, stiffness on rising, alteration
in the manner of running, "bunny hops", pain after exercise and resentment
to patting of hind quarters.
The arc of movement of the hind
leg becomes greatly decreased, and as degenerative joint disease develops
the thigh muscles atrophy.
The degree of lameness becomes worse
after a couple of years and is aggravated by cold and damp weather.
It is possible for CHD to be present
in dogs who show no visible lameness or gait abnormality.
It is a complex inherited disease
weather the degree of severity of Dysplasia in the parents directly influences
the frequency and severity in the pups. Even mild dysplasia in one parent
will affect the risk of dysplasia developing in the progeny.
A high energy diet leading to rapid
growing or overweight pups has a greater chance of producing dysplasia,
especially if the growth spurt occurs at a sensitive time in skeletal
and muscular development.
poor pelvic muscle mass and abnormal
pelvis angulation will affect the hip joint.
Excessive activity in the young
animal, especially if overweight or in the presence of exaggerated joint
laxity can aggravate dysplasia.
Calcium intake may be an important
factor with both excessive or insufficient calcium being detrimental
to joint development.
Grading of Hip Dysplasia
By radiographic evaluation of the
hips it may be diagnosed as early as a few months of age. In South
Africa certification may be done from one year of age. Correct positioning
of the dog is important and is facilitated by sedation and anaesthesia.
Palpitation of joint laxity in the
young pup is often one of the first diagnostic signs of CHD. This
is also facilitated by anaesthesia.
South Africa: No signs of hip
Transitional / Borderline - very minor incongruity
- mild shallowing of acetablum and flattening
- moderate changes
- Severe changes
- Very severe with sublaxtion
Nine different areas of the hips are evaluated, each obtaining a score
of 0 = normal to 6 - Very bad. Thus the best hips score 0/0 and the worst
* Resectioning of pectineal
muscle or tendon - the most common method used in less severe cases - affords
significant functional improvement and reduction of pain within 24 to 72
hours but will not stop the further development of arthritic changes and
thus lameness may return later in the dog's life, especially
in colder weather.
No therapeutic or surgical treatment
will restore totally normal function. However, some measure of relief can
usually be given to the dog crippled with CHD
Treatment is aimed at alleviating
the pain caused by the degenerating joint disease by avoiding cold, damp
areas; judicious exercise to maintain muscle tone with care not to
overexert the joints; allowing adequate periods of rest; reducing weight
in the obese dog; using analgesic and anti-inflammatory drugs; and
resorting to surgical procedures where these methods are no longer effective.
Surgical procedures include the
* Resectioning of
femoral head -for severe dysplastic arthritic changes. This is occasionally
done on both sides and is generally more successful on the lighter type
osteotomy of the pelvis or femoral head. This surgery is the best
best for cases performed between four to eight months and is not worse
than grade II or III.
* Hip prosthesis
which is expensive and to date results have not been impressive.
normal: normal matings led to 18 percent dysplastic offspring;
As CHD is genetically influenced,
radiographs can be used as an indication of a dog's desirablitity for breeding.
The breeding of two radiographically
HD free dogs will not necessarily guarantee that their offspring
will be HD free. An HD control programme in sweden showed
normal: dysplastic matings led to 59 percent dysplastic offspring.
dysplastic: dysplastic matings led to 87 percent dysplatic