Hip Dysplasia
Hip Dysplasia is an abnormal skeletal condition in which the ball and socket joint of the hips fails to develop properly which results in rubbing and grinding instead of the joint sliding smoothly. Over time, this results in deterioration and loss of function of the joint. There are various grades of dysplasia. Some dogs may have very mild or borderline hips and show little to no symptoms. While others may have severe hip dysplasia and may have pain and other symptoms. Severe dysplasia often requires surgery and other medical interventions with the most common surgeries being Double or triple pelvic osteotomy (DPO/TPO), Femoral head ostectomy (FHO) and Total hip replacement (THR) surgeries. The owner may opt for humane euthanization of the animal instead.
How prevalent is Hip Dysplasia in Norwegian Buhunds in North America?
First one must know about the two most common methods for evaluating hip joints in dogs.
The Orthopedic Foundation for Animals (OFA) Method
The Orthopedic Foundation for Animals (OFA) is the more well-known and "AKC Accepted" option - AKC Accepted meaning that passing results will show up on AKC pedigrees.
The OFA relies on qualitative interpretations of a single radiograph of the dogs hips using the OFA seven-point hip joint scoring system. The radiograph is independently evaluated by three randomly selected, board-certified veterinary radiologists from a pool of 20 to 25 consulting radiologists throughout the USA. The dog's hips are scored Excellent, Good, Fair, Borderline (unclear), Mild, Moderate, or Severe based on these three interpretations.
Examples would be:
There are approximately 9 different anatomic areas of the hip that are evaluated.
As of December 2017, 252 radiographs had been submitted to the Orthopedic Foundation for Animals (OFA) for evaluation, here were the results:
90.1% - "Normal" (OFA Excellent, Good, Fair)
9.1% - "Abnormal" (OFA Mild, Moderate, Severe)
0.8% - "Equivocal" (OFA Borderline which means "Not clear. Usually more incongruency present than what occurs in a fair but there are no arthritic changes present that definitively diagnose the hip joint being dysplastic.")
Even if all the Norwegian Buhunds whose results came back as "Equivocal" did turn out to have dysplasia, this means that less than 10.0% of all buhunds have some level of hip dysplasia when evaluated by the OFA using the OFA's methods.
The AIS PennHIP Method
The second most common method of evaluating dogs for hip dysplasia in North America is the PennHIP method currently being provided by Antech Imaging Services.
Comparing the two methods
How prevalent is Hip Dysplasia in Norwegian Buhunds in North America?
First one must know about the two most common methods for evaluating hip joints in dogs.
The Orthopedic Foundation for Animals (OFA) Method
The Orthopedic Foundation for Animals (OFA) is the more well-known and "AKC Accepted" option - AKC Accepted meaning that passing results will show up on AKC pedigrees.
The OFA relies on qualitative interpretations of a single radiograph of the dogs hips using the OFA seven-point hip joint scoring system. The radiograph is independently evaluated by three randomly selected, board-certified veterinary radiologists from a pool of 20 to 25 consulting radiologists throughout the USA. The dog's hips are scored Excellent, Good, Fair, Borderline (unclear), Mild, Moderate, or Severe based on these three interpretations.
Examples would be:
- Two radiologists reported Excellent, one Good—the final grade would be Excellent
- One radiologist reported Excellent, one Good, one Fair—the final grade would be Good
- One radiologist reported Fair, two radiologists reported Mild—the final grade would be Mild
There are approximately 9 different anatomic areas of the hip that are evaluated.
- Craniolateral acetabular rim
- Cranial acetabular margin
- Femoral head (hip ball)
- Fovea capitis (normal flattened area on hip ball)
- Acetabular notch
- Caudal acetabular rim
- Dorsal acetabular margin
- Junction of femoral head and neck
- Trochanteric fossa
As of December 2017, 252 radiographs had been submitted to the Orthopedic Foundation for Animals (OFA) for evaluation, here were the results:
90.1% - "Normal" (OFA Excellent, Good, Fair)
9.1% - "Abnormal" (OFA Mild, Moderate, Severe)
0.8% - "Equivocal" (OFA Borderline which means "Not clear. Usually more incongruency present than what occurs in a fair but there are no arthritic changes present that definitively diagnose the hip joint being dysplastic.")
Even if all the Norwegian Buhunds whose results came back as "Equivocal" did turn out to have dysplasia, this means that less than 10.0% of all buhunds have some level of hip dysplasia when evaluated by the OFA using the OFA's methods.
The AIS PennHIP Method
The second most common method of evaluating dogs for hip dysplasia in North America is the PennHIP method currently being provided by Antech Imaging Services.
Comparing the two methods