Hip Dysplasia (HD) is an inherited joint disease that affects hip and elbow joints. The term dysplasia, means malformed, irregular, abnormal. Symptoms develop as a result of arthritic changes in the shallow, abnormal hip joint resulting in abnormal wear. HD is multi-dimensional, with environment and nutrition ‘suspect’ in the development of symptoms. A complicated inheritance pattern has led to decades of worldwide research on this malady of all breeds. It is seen more frequently in larger breeds, but smaller or even toy breeds are not immune.
For decades, screening hips for good health has been done worldwide to exclude affected animals in breeding programs. Building pedigrees of “clear” dogs will decrease the potential of producing the disease in future generations. In this country we have two registries who examine, and certify hips as appropriate for breeding. Breed club recommendations generally mirror the recommendations from these organizations.
The Orthopedic Foundation of America (OFA) was an early registry to certify healthy hips in the USA. They have three levels of “passing” hip evaluations, Excellent, Good, and Fair. They have six levels of non- passing evaluations, borderline dysplasia, mild dysplasia, moderate dysplasia, severe dysplasia, indeterminate, and avascular necrosis. These are pass fail results, and all failing reports are recommended to not breed. The passing results are recommended as acceptable for breeding. Dogs must be two years old to have this examination done, but can have “preliminary” evaluations done for dogs under two years old. This is a single extended view radiograph exam for joint irregularities, depth of joint, and developmental changes to the joint. It can be done with or without sedation of the dog. Generally only passing results appear on the OFA registry, and a number and grade issued. It is possible to use this as an open data base, and non passing results be posted on your dogs. Click here for the OFA form to do this.
University of Pennsylvania Hip Improvement Program (PennHip) is a more recent organization who has developed a system of measuring the “looseness” of the hip joints, as a indication of future hip health. This is not a pass/fail examination, and they do not give “breeding recommendations”. The results for each breed are averaged, and a scale is created with a median or “average,” for that breed. PennHip “proposes” that dogs in the upper, or “tighter” end of that scale to be used for breeding, and those below, the “looser” end of the scale, be eliminated from breeding programs. This median is evaluated every six months, and that number will change, up or down, reflecting the scores they have on record for each breed. The goal is to see the scores and the median improve, become “tighter”, as overall hips improve through breeding. They use three radiograph views (extended, compression, and distracted) in this evaluation, and can be done any time after four months of age. The older the dog at examination, the higher the correlation of their projection to actual hip health of the growing dog. They do not have a public database, or “registry”, but it is reported that they hope to develop one in the future. This exam can only be done on a totally sedated dog.
A dog with Hip Dysplasia can lead a long and pain free life. Muscle strength, size of the dog, activity, and nutrition all play a role in developing arthritic changes and pain. Surgery is an option to relieve pain, and increase mobility for a symptomatic dog.
To increase the likelihood of producing puppies free of hip problems, both parents should be examined free of HD. A multi generation pedigree of dogs examined free of HD is most likely to produce HD free puppies. None the less, there is no guarantee, as the mode of inheritance is very complex. The incidence of Hip Dysplasia in German Pinschers is low but is not unknown.
CLICK here for a video of correct OFA x-ray technique.