Health checks and certifications are an important part of breeding healthy puppies. Hip dysplasia is the most common and widespread health concern in our three breeds, and the most common method of checking for hip dysplasia is an x-ray taken when a dog is 24 months or older, which typically is sent to OFA (Orthopedic Foundation for Animals) for evaluation. The x-ray is evaluated by three veterinarians (which differ and/or rotate after a period of time), who each give an opinion ranging from Excellent to Severe. Excellent, Good, and Fair evaluations receive an OFA number as passing (no hip dysplasia). Borderline, Mild, Moderate, and Severe evaluations indicate a degree of abnormality is evident and those dogs do not receive OFA and certification numbers. However, breeding two OFA-certified dogs are in no way a guarantee that their puppies will be clear of hip dysplasia. In fact, two OFA Excellent dogs can produce dysplastic offspring.
I’d like to explain our decision to use PennHip here at Nosam
A big challenge with using OFA occurs when vets incorrectly line up the dog's hips on an X-ray. Any veterinarian can perform OFA radiographs – certification is not required. PennHip actually requires the vet to become certified to properly position dogs correctly for the X-rays. A PennHip evaluation not only reports as dysplastic those dogs with bone and cartilage abnormalities but also points to the risk of the dog developing such radiographic signs later. While PennHip does measure laxity, it also looks at the integrity of the joint for dysplasia. If a dog’s hip joint’s femoral head looks tight and round on an OFA film but shows considerable laxity on the PennHip view, it’s viewed as having a future risk for degenerative joint disease.
The simple fact that you can physically manipulate a dog's hips and take multiple x-rays to make the hips look better and send the best one off to OFA so that your breeding prospect will pass is the problem we have with OFA. OFA is dependent on the people reading the x-rays and their personal consensus about the score. If you do pennhip, the answer you get will not change because it's math and not up for opinion or debate.
The PennHIP method has also shown that breeding dogs to improve the hip joint laxity does help improve hips in dogs of succeeding generations. Dogs are rated from 0 (no laxity) to 1 (total laxity). Each breed has a median score, our breeds are listed below! The median scores can adjust slightly as more dogs are added to the database). A score of .30 or less is a strong indication that the dog is highly unlikely to develop hip dysplasia.
With all this being said, while everyone can agree that only healthy dogs should be bred, hip x-rays are just one small part of evaluating a dog for breeding potential. There are many aspects of a dog's health, temperament, hunting abilities, and structure that are important to consider when planning a breeding. Every dog has genetic faults, upon which responsible breeders must strive to improve for each succeeding generation. PennHIP has shown itself to be a proven tool for improving hips.
AIS PennHIP testing is accurate in puppies as young as 16 weeks of age. It gives an estimate of the risk for painful osteoarthritis (OA) of canine hip dysplasia (CHD) later in life. With this information, preventive and palliative strategies can be recommended by the PennHIP-trained veterinarian.
All dogs can benefit from PennHIP testing. For pet dogs found to be at risk to develop hip OA, early intervention can help prevent or lessen the severity of CHD. For working/service dogs, identifying a dog with healthy hips can extend the working life of the dog. For breeding dogs, early detection of at-risk hips can allow the breeder to make early, informed decisions as to which dogs to keep in breeding programs.
OFA does not give an actual grade until the dog is 24 months of age. OFA certification is no guarantee that a dog will not develop hip dysplasia symptoms in the future and does not guarantee that the offspring will not develop hip dysplasia. The PennHIP method of evaluation is more accurate than the current standard in its ability to predict the onset of osteoarthritis (OA). The procedure is more objective (comparing numbers) than OFA radiographs.
The PennHip radiograph series consists of 3 views: Hip-extended view (same as OFA view), compression view, and forced distraction view. One could complete both PennHip and OFA screens in the same radiograph session by taking an additional extended view to send to the OFA. Radiographs for submission to PennHip may only be taken by PennHip-trained and certified veterinarians.
The Distraction Index (DI) as determined by the PennHIP method is the most reliable indicator of future hip osteoarthritis.
In a study comparing factors such as age, breed, weight, gender, distraction index, and Norberg angle (another method of measuring hip laxity based on the conventional OFA-type x-ray), it was found that the distraction index had the highest correlation (predictive power) with future development of osteoarthritis irrespective of age at the time of PennHIP evaluation.
The current PennHip database consists 1079 Vizslas Lowest DI (desirable) 0.24 Mean DI (average) 0.45 Highest DI (undesirable) 0.68
The current PennHip database consists of 1289 GSPS Lowest DI (desirable) 0.19 Mean DI (average) .32 Highest DI .60