Dysplasia is a condition caused by abnormal development, in this case, of a joint. Hip and Elbow dysplasia (HD and ED) are conditions common in rapidly growing large and giant breed dogs, but can also affect smaller breeds and cats.
Clinical signs to look out for
Clinical signs include lameness, joint pain and an inability to exercise properly. Both conditions are caused by genetic factors and are influenced by environmental conditions such as excess calorie intake and exercise. Instead of normal development and healthy cartilage, the abnormal joint wears prematurely and leads to potentially crippling arthritis from an early age.
Currently there are no reliable genetic tests for either disease, hence radiographic (x-ray) scoring schemes are still used to select dogs with better than average hips/elbows for breeding.
Dogs scored for elbow dysplasia will require an outpatient visit to their veterinarian. Owners will need to provide their dog’s registration documents (if pedigree, though non-pedigree dogs can still be scored) and the veterinarian is required to identify the dog by microchip scanner and then complete the certification documentation. The dog will be sedated for accurate scoring. The x-rays are sent to the elbow panel, who will evaluate, grade and certify the degree of osteoarthritic changes. The results are posted to the veterinarian.
In the case of a dispute, an independent veterinary radiologist will audit the submission. Results are recorded in the NZVA register which provides information by breed (see the resources in the resources section below).
Digital submissions are to be in DICOM format only; clearly name the individual files eg. Left Elbow, Right Elbow, Hips, microchip number and registered name of the dog (if applicable). Please do not place sticky labels onto the CD, these will be rejected. Identifying labels can be placed on the CD case.
Find more information to help you with submissions in the resources section at the end of this page.
The previous NZVA Hip Dysplasia scheme was based on the Willis/BVA scheme which dates back to the 1960s. Since then our knowledge of Hip Dysplasia has grown and the role of hip laxity (looseness of the hip joint) has been identified as a key contributor. Whilst it has definitely helped us remove badly affected dogs from the breeding pool, the existing Willis/BVA scheme (and also the American OFA and Australian schemes) underestimates the degree of laxity.
The PennHIP method targets laxity by measuring distraction index and its heritability, which influences the speed at which genetic improvement can be obtained.
Veterinarians must complete a training course and accreditation programme to take PennHIP radiographs.