CANINE HIP DYSPLASIA

Many newcomers to the dog fancy may be wondering about references to hip dysplasia, X-rays and certified normal. The following was written by Canada's foremost authority on the problem of canine hip dysplasia.

The term hip dysplasia means malformation of the hip and describes a developmental disease of the hip joints in young dogs of many different breeds. Unsound hip joints are a common problem in working and sporting breeds, and hip dysplasia is a serious problem in any dog that is to be trained for a demanding activity.

SIGNS: Signs of hip dysplasia cannot be detected in the newborn puppy, but may appear in the rapid growth period between four and nine months of age. Signs of the disease can vary widely from slight irregularities of gait to crippling hip disease. Improvement or even apparent disappearance of lameness can occur as the dog matures but arthritis of the hip joints is usually present in the older dog with dysplasia.

DIAGNOSIS: The best way to determine the condition of the hip joints of a dog is by good
X-ray examination. Sedation or a short acting anesthetic may be necessary to restrain the dog so that a diagnostic film can be taken.

TREATMENT: Your veterinarian may suggest rest and supportive care as a medical treatment during the acute phase of the disease. Surgical treatment for the relief of pain may be of value if discomfort persists. Moderate and regular exercise, control of excessive weight and anti - inflammatory drugs are helpful in the management of arthritis associated with hip dysplasia in the older dog.

GENETICS: Hip dysplasia is an inherited defect with a polygenic mode of inheritance. The degree of inheritability is moderate in nature and the condition of the hip joints can be modified by environmental factors such as over nutrition and excessively rapid growth. As with any quantitative trait, hip joint conformation can range from good to bad with any all shades in between.

CONTROL: In as much as faulty hip joints are not readily observable, dogs intended for breeding should be x-rayed when mature to select for sound hips. Eighteen months of age is considered to be the minimum age for radiographic certification of desirable conformation with respect to canine hip dysplasia. Ideally, dogs with hip dysplasia should not be used for breeding.

The following drawings from left to right are; a Normal Socket, Grade 2 Dysplasia, and Grade 3 or 4 Dysplasia. A drawing of Grade 1 Dysplasia is not included because it requires a radiologist to differentiate the mild Grade 1 from the Normal.
It is for this reason that the OVC and the Orthopedic Foundation for Animals (OFA) in the United States have set up services whereby X-ray plates can be certified by trained radiologists.





P. W. Pennock, DVM (Radiologist)
Ontario Veterinary College (OVC)
Guelph, Ontario, Canada.

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