What is it?
Hip dysplasia is an abnormally developed hip joint with a shallow hip joint cup and changes in the shape of the hip joint ball. Cats can get the disease but you see it most often in dogs by far. A dog can get painful arthritis from the malformed hip joint and symptoms include limping, difficulty standing or walking after getting up, decreased activity, or a bunny-hop gait - very painful indeed.
Hip dysplasia is an inherited disease but often you can't tell how severe the disease will be by looking at the parents. As well, not all dogs that inherit the disease end up with symptoms, indicating a combination of genetics and the dogs environment affecting the degree of the disease. We do know that dogs with no genetic predisposition do not develop hip dysplasia - hooray!
At present, the strongest environmental factor appears to be to rapid growth and weight gain. In a 2004 study done by the Purina Pet Institute in Labrador Retrievers, the incidence of hip dysplasia was reduced by half in a group of puppies fed 25% less than a control group which was allowed to eat free choice. Click here for a nice summary (in english, not scientific language!). Strictly controlling your dog's diet is something you can do to make a significant difference in your dog's health.
How do I know if my dog has this disease?
Unfortunately, you cannot tell if a dog has the disease at birth as it takes several months to reveal itself.
There are two techniques currently used to detect hip dysplasia:
- the standard X-ray view used in Orthopedic Foundation for Animals (OFA) testing
- specific X-ray techniques used by the University of Pennsylvania Hip Improvement Program (PennHIP).
The Penn Hip method appears to be a better method for judging hip dysplasia, as early as 4 months of age in some puppies.
For dogs that show symptoms before they have finished growing, glucosamine based nutritional supplements may help to reduce the arthritis symptoms that develop later in life. Surgery can also be helpful.
Dogs that show signs at older ages may require other drug treatments such as aspirin/codeine combinations, phenylbutazone, glycosaminoglycosans and corticosteroids, although these have to be watched carefully as they can have serious side effects.
Surgical options include excision arthroplasty, where the the head of the leg bone is removed and reshaped or replaced, femoral head ostectomy (FHO), where the head of the bone is not replaced, and pelvic rotation (also known as triple pelvic osteotomy, or pubic symphodesis) where the hip socket is realigned. These procedures need to be done at young ages and are most successful for smaller dogs and cats. There also hip replacement, which has the highest success rate, particularly for larger dogs or more severe cases but it is expensive.
As usual, if you see anything that concerns you about your cat or dog's health, talk to your vet.
Pet insurance considerations
If your pet insurer excludes hereditary conditions, then they exclude hip dysplasia, even in mixed breed dogs and cats. Make sure to check your policy.
For the record, Embrace Pet Insurance covers genetic and hereditary conditions, such as hip dysplasia, as long as your pet has not been diagnosed or shown signs of the condition before you get your insurance or in the waiting period. We do not exclude genetic conditions.