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Hip – and Elbow dysplasia
Hip dysplasia is one of the most common skeletal diseases in dogs and
affects millions of dogs worldwide. As the disease progresses, a dog's
hip joints degenerate, causing increased pain and mobility issues for
the dog. If left untreated, a dog will eventually be unable to use
his/her hind legs and suffer extreme pain. However, the vast majority of
dogs with hip dysplasia can lead full and active lives if the disease is
diagnosed early enough and proper treatment is given and maintained.
The condition is caused due to failure of the hip ball (head of femur)
to fit properly into the hip socket (acetabulum). The ball may be loose
and this results in excessive rubbing and eventually osteoarthritis of
the joints, which eventually leading to loss of function in the hip
joints.
Hip dysplasia is caused by a number of genetic and environmental
factors.
• Some dogs can be born with hip dysplasia (often referred to as early
onset hip dysplasia). From an inheritance perspective, it is a complex
disorder with multiple genes involved. Therefore, it is not something
easily eradicated from a particular breed or lineage.
• Dogs can also develop the disease in later years with the onset of
arthritic conditions (often referred to as later onset hip dysplasia).
• Environmental factors can also cause hip dysplasia. These can include:
rapid weight gain and obesity, nutritional factors, poor hind limb
muscle development, pelvic injuries, or repetitive strain injuries.
Early onset cases of hip dysplasia usually develop after four months of
age. In young dogs, there is a laxity or joint looseness that develops
as the dog grows. For later onset cases, the cause is usually due to a
form of arthritis called osteoarthritis, which causes the joint
cartilage to deteriorate.
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Responsible breeders have their breeding dogs X-rayed for HD and these
X-rays are then graded by a qualified radiologist. Every breeder must be
able to use own discretion to breed or not with certain grading.
Genetics, bloodlines, breeding or inheritance is not the only cause of
HD. Environmental factors sometimes play a bigger role than anything
else. This includes the wrong diet, too little or too much. Obesity.
Excessive exercise or rough playing at too early age. Slippery floors.
Incorrect handling of a puppy when picked up and put down.
Elbow dysplasia is a defect of the growth process of the elbow joint.
Clinical signs of ED can start as early as from 4 months of age. Dogs
with ED may or may not show lameness or any other form of discomfort in
the front leg. The elbow might even be swollen and painful on touch.
Responsible breeder also has their breeding dogs X-rayed for ED, the
same as for HD.
PRA-prcd and EIC
PRA has several different forms, but progressive rod cone degeneration (
PRA-prcd) is the most common in Labradors. The age at which clinical
signs of PRA-prcd become noticeable varies. Some experts believe that
signs are visible by physical examination between 3 and 6 years of age.
In PRA-prcd, retinal receptor cells responsible for vision develop and
function normally in early life, but at some point in mid to later life
they degenerate and die. These receptor cells are two types: rods and
cones. The rods are responsible for vision in low light levels and they
die first. Thus affected dogs initially have difficulty seeing in dim
light. Eventually the cones, which are more important for detail,
movement and color vision, will follow. The dog gradually loses vision
in bright light too, until becoming completely blind.
EIC (Exercise-induced collapse) is a recently recognized disorder of
increasing significance in Labradors.
Dogs with EIC (Affected) develop muscle weakness, in coordination and
life-threatening collapse after just a few minutes of intense or
strenuous exercise. This collapse can range from dragging of the hind
legs to complete collapse. Affected dogs can tolerate mild to moderate
exercise, but just for 5 to 20 minutes of strenuous activity can induce
weakness or collapse.
Signs to look for include:
• Weakness after 5-15 minutes of strenuous exercise
• Lack of coordination
• Dragging of rear legs
• Dazed, confused appearance
• Collapse
• Staggering, falling to one side, or difficulty maintaining balance is
common during recovery
There are DNA testing available in South Africa for PRA-prcd and EIC and
a breeder should not have any excuse for breeding affected puppies.
Table 1: Possible breeding scenarios for PRA-prcd and EIC |
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Parent 2 genotype |
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Parent 1 genotype |
Clear |
Carrier |
Affected |
Clear |
All Clear |
50% Clear
50% Carrier |
All carriers |
Carrier |
50% Clear
50% Carrier |
25% Affected
25% Clear
50% Carrier |
50% Carrier
50% Affected |
Affected |
All Carrier |
50% Carrier
50% Affected |
All Affected |
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