Hip Dysplasia
Veterinarians and responsible breeders of purebred dogs are well aware that hip dysplasia and other inherited diseases can be controlled by careful, selective breeding programs. They know that breeding hip clear dogs to hip clear females will produce fewer affected offspring than breeding affected dogs together. They also know the value of the family history for normal hip status when dogs are to be used in a breeding program.
The Orthopedic Foundation for Animals (OFA) is a voluntary database serving all breeds and has records on the hip status of individual dogs over many generations. This information assists the breeder in reducing the frequency of HD.
In addition to their Hip Dysplasia database, OFA offers other databases such as Elbow Dysplasia, Autoimmune Thyroiditis, Cardiac Disease and Patella Luxation. They also run an Open Health Registry called Canine Health Information Center (CHIC) where the requirements for inclusion to this database is stipulated by each AKC breed Parent Club.
Over the years, progress in hip joint phenotype of dogs in the USA was evident when the percentage of dogs with excellent hip joint phenotype increased and the percentage of dogs with hip dysplasia decreased. Ideally, the quickest method of reducing the incidence of an undesirable trait (in this discussion, hip dysplasia) is to know the hip status of relatives and siblings before making a breeding decision.
The use of preliminary radiographs as early as four months of age can be used by breeders to add valuable information on the hip status of dogs they choose to use in a breeding program.
In the year 2001, 87.4% of Cavaliers passed their OFA hip screenings and 12.6% of them failed. Since x-ray results are not always sent to OFA by breeders whose vets consider them dysplastic, this number is not exact and one can assume that 12.6% is a low figure.
Typically, adolescent Cavaliers with HD can show symptoms of pain if their hip conformation is abnormal. Unless their hips are particularly severe, these episodes resolve themselves as these Cavaliers become adults. Management of HD through nutrition, supplements and various anti inflammatory drugs has been known to be successful and HD surgery is not usually performed. When Cavaliers with HD become older, their arthritis in the dysplastic hips will cause them severe pain. Cavaliers with hip dysplasia should never be bred from.
Links:
Orthopedic Foundation for Animals (OFA): http://www.ofa.org
Canine Health Information Center (CHIC): http://www.caninehealthinfo.org/