Hip Score testing and scoring is a very understood issue. For what its worth, we here at Darkstone Kennel will provide with you with our thoughts and "opinions" on the topic.
Hip Score Opinion
First, any type of legitimate hip scoring agency will produce a legitimate hip score for the purposes of evaluating breeding stock. In North America, there are two primary choices: the OFA and PennHip. The OVC (Ontario Veterinary College....Canada) is also a very valid third choice, and will score both hips and Elbows in the same manner as the OFA, and actually offers an online submission option for digital x-rays. A valid passing hip score from any of these organizations is very acceptable, the rest is just "preference," or something to argue about.
Each organization does things a little differently. You will find supporters and detractors of each method, typically based on their previous personal success or failures using one method over another. The PennHip people will claim they have the most scientific method, using three different positions, and giving a specific measurement for joint laxity, while the OFA and OVC use a panel of three different vets for each case to assess the single position Xray on a wide variety of points within the x-ray, and then deliver a general "rating." The PennHip tends to be more costly (as it is a for profit organization, unlike the not for profit OFA or OVC), and the dog's joints can be nearly functionally dislocated briefly during the process, which tends to upset some people, or at the least, allow people to claim it is not a test based on "natural" use case. Personally, we are neutral on the topic of "which method is best," as to us, one method is just as good as another.
The Europeans have their own rating system, with hips being rates as HD-A, HD-B, etc, which is comparable to the OFA rating scale. Importantly, many feel from their own years of experience in large breeds that the European scale is not as rigid, and therefore easier to gain a passing/acceptable score. Some number of people we know who have imported larger numbers of dogs with European HD-A, or HD-B scores, and then have a comparable OFA done, typically find that an HD-A score will equal an OFA "Good," an HD-B score equal an OFA "Fair," and so on. In Europe, and HD-C hip is considered to be just fine for breeding purposes, as it typically indicates a bit more laxity in the hip joints, but no DJD, but would typically equate to an OFA failing test rated as "borderline" or "minor dysplasia."
There are two things of interest in a hip scoring exercise: the degree of "laxity" or joint tightness/looseness in the hip joint (how deeply the femur is positioned in the hip socket and how much room is around the same), and whether or not there are any signs of degenerative joint disease (DJD) present, which will continue to degenerate and cause the dog pain. The larger the breed, the more prone they are to laxity, and while laxity may be a pre-cursor to some abnormal wear and tear in a joint over the dog's life, it does not cause any pain in an of itself. A deformed femur bone (not well rounded or worn), or poor hip socket (not deep enough or nearly non-existent, deformed, etc.), both indications of DJD, will cause pain as the joint will become arthritic and will continue to wear excessively with age.
The PennHip scores are pretty straightforward, as an overall laxity score for each hip is generated. If there is no DJD present, which is also indicated separately on the result as being present or not, then the hip score is given a "percentile" ranking against all other dogs of that breed who have previously had a PennHip score. As the pool of scores gets larger, it becomes harder to get a higher "percentile" score over time. As a rule of thumb, the acceptable range of PennHip scores, in terms of hip laxity for the Cane Corso, has tended to be in the .25 - .65 range, as long as no DJD is present in the joint. The lower score is obviously a tighter hip and in the higher percentile of the group, while the higher scores would still be acceptable. The "rule of thumb" we have always historically seen in the breed is that a score above .65 should probably not be considered a "passing" score in terms of the laxity of a joint...though some would push that up to .70. This is particularly true if it is just one hip with the higher score, while the "other hip" demonstrates a very acceptable score. In the opinion of many people, this is an indication of an "environmental" issue that has caused the imbalance in the hip girdle, not genetics. That is one issue with the PennHip: there is no pass or fail on the score as long as there is no DJD present. Many dogs in the .40-.65 range tend to score an OFA "good" if they are done on both...but there are other factors, such as the roundness of the femur bone, the shape of the hip sockets, etc, which come into play on an OFA/OVC rating, not just the joint tightness/laxity.
The OFA rating, the last time we checked, was the only one that was AKC approved, if that matters to a breeder/buyer at all. Frankly, we don't think it matters all that much. While the OFA score ranges anywhere from a fail/borderline to the range of fair/good/excellent, it really comes down to: does the dog pass or not? What people don't realize is that on an OFA rating with three reviewers, the 'lowest common denominator" score is what is given out as the actual final rating. So, if you have two raters who score a dog as a 'good' and one rater scores the dog "fair," the dog will be scored as a "fair." The bottom line with an OFA score is simple: a "fair" rating is a very acceptable passing score for a dog, particularly in a large, still evolving breed like the Cane Corso that still lacks a large pool of hip scored, well bred, structurally and temperamentally sound dogs...and would be more prone to joint laxity as a breed simply due to their size.
Therefore, in our opinion does an OFA "fair" rating make it a poor/borderline hip example? Absolutely not! It is a fully acceptable, passing hip score, and should be absolutely considered for use in a breeding program as long as the dog meets the rest of the criteria for a "breed worthy" specimen. The OFA also goes through some cycles over the years, depending on what vets they have in their reviewing group. At some points in time, they seem to score quite reasonably, and at other times, they seem to want to score dogs ridiculously hard. What we have heard from a few vets and breeders lately is that they are currently scoring very hard, and on shots they have taken and sent in where they would all bet money a dog would go "good" or "excellent," based on what they have been seeing coming back for many years, they have recently been coming back "fair" in many cases. So yes, some subjectivity does come into play, which can impact a hip rating either negatively or positively. So, depending on "when" a dog is scored in a point in time, in relation to the vets doing the scoring at that time, results can vary to some degree. Remember, it only takes one vet/score per assessing group to ultimately knock an otherwise excellent score to a good, a good to a fair, or a fair to a borderline/fail. We have been looking at hip Xrays for more than 15 years....and typically have had a pretty good idea of what scores would come back, but lately, it seems like everyone we know is getting some surprises. One can always choose to "re-submit" those Xrays in the hope of getting a different assessment group, and potentially a higher score, though that can backfire, as we have known people who got a "fair" the first time, then were failed the second time when they hoped to get a "good" upon re-submission.
As most long time breeders of large breed dogs know, it is just a "probability game" when it comes to achieving certain "scores" when breeding hip/joint genetics. From what we can remember, if you breed an excellent to an excellent, you only have a 20% greater chance of getting a passing hip score in the offspring than if you bred an excellent to a fair or even borderline/fail scored dog. Conversely, again if memory serves, there is a greater statistical probability of producing a dog with an "excellent" score if you breed a dog with an excellent rating to a fair/borderline rating than there is if you breed two excellent scores together. This probability rule of thumb will also differ greatly by breed, and size of breed, as the larger the dog, the greater propensity for laxity in the joints.
So, it is complicated in that way. It is also probably just as or more important to ensure that the grandparents and great grandparents of the dogs have decent hip scores, as well as their siblings, as genetic stability in hips is set over generations, not just one breeding. One or two dogs in a litter or a line does not make a pattern in either direction. It is also much harder with a breed like the Corso, as the breed is not yet mature enough out of the recovery period to show a huge degree of replicability when breeding. Just when you think you know what the traits of a breeding pair will be, based on their pedigrees, etc., they throw something completely different, or the variation in a litter will be huge. That is just reality at this point in the breed's history, so consistency in hip scoring will also be lower than in other more established breeds.
There also exists a lot of controversy over nutrition and environment, with many very knowledgeable people feeling that those issues will contribute to joint scores/health in the adults as much as genetics. In fact, we have read articles that state that since the inception of hip score testing, that the overall degree of hip dysplasia across all breeds has NOT improved measurably. In fact, the PennHip people claim that after 20 years of OFA testing in many breeds, the overall hip structures have not improved measurably (which is a marketing ploy for their own services....we have no idea whether the claim is absolutely true or not. Remember, there are "lies; damn lies; and statistics...). Personally, we find that hard to believe. However, those who focus on nutrition and environmental issues in trying to ensure joint health will find statistical probabilities to demonstrate that hip testing shows a slightly better than chance probability of increasing hip/joint health, while at the same time, they can alternatively demonstrate that nutritional decline in the past (moving from raw or better diets to highly processed diets filled with garbage in the 70s and 80s) led to many breeds showing significant declines in hip scores, while the newer generations feeding raw or very high quality processed food diets and/or supplementation are once again showing better hips/joints. Depending on what school of thought you come from or adhere to, you can typically find some way to make the statistics work in your favor, so for the average person doing some basic research on the issue, it can be very muddy.
A final bit of controversy we have heard for years in a lot of large breeds relates to bi-lateral versus unilateral hip score issues. For instance, if you have only one hip showing some elevated degree of laxity/looseness on a score, while the other hip is tighter or within typically acceptable ranges (unilateral), many very knowledgeable people who have been breeding working/large breeds for a lot of years will tell you that this situation is NOT related to genetics, and was caused by nutrition/environment/injury, while a bilateral (both hips) issue related to excess laxity is clearly genetic in origin. One canine/animal chiropractor that we take our young pups to for adjustments at young ages to ensure their hip girdles, spines, etc. are properly aligned to start things off, is very certain that most "unilateral" hip issues are caused by a misalignment of the hip girdle at a young age that is not caught, and as the dog is forced to compensate for the same as they age and grow rapidly, that the one side of the hip region shows issues and the other doesn´t. This misalignment can happen in the womb, or even when the pup is squeezed out of the birth canal, or just through the mother laying on the dogs, play, etc. This woman has an M.A. in animal physiology, and is probably one of the most highly thought of people in her field in North America, with plans on publishing several papers on this specific topic in Veterinary Medical Journals in the future, based on her own research/experience...so we do listen to her theories on the subject.
We must apologize if this information confuses you even more, but that is the reality of "hip scoring" in any large breed. Frankly, if you want our "two cent opinion" on the topic: an ugly dog with a nice hip score is just that....an ugly dog with a nice hip score. It is great if you want a pet, but it should not be bred just because it has a hip score. A hip score is only one of many factors in making a well thought out breeding decision. At the current stage of the Cane Corso, where there are still not that many great, balanced dogs out there yet, the hip score issue should in reality probably still carry somewhat less weight than in other long time established breeds. That is one reason few breeders do elbows, it is not that big of a deal in the Cane Corso breed yet, as people are still trying to get the hips cleaned up, so elbows have taken a back seat. That is not to say any ethical breeder should not be doing hip scores, or breeding dogs with DJD. But let us propose a very common scenario facing many top breeders: what if they have a stunning example of the breed, with only minor laxity in the hip scores (no DJD), or even showing mild laxity in only one hip, which many across the working dog world will tell you is NOT genetic in origin, what do they do then when making an intelligent, ethical breeding decision? That's when tough, ethical decisions have to be made as to whether that dog would, under very tight breeding conditions, have the ability to improve the breed via their use in a breeding pool. These are the kinds of "ethical dilemma" breeding decisions that even the best breeders in the Corso world face on a regular basis.
In the Rottweiler world we have participated in for far longer than the Corso breed, the same issues exist, just a bit differently. Hips are no longer a big issue across the top blood lines in the breed pool, and there exists a large pool of high quality dogs to draw from to enhance a breeding program/genetics for the average breeder. The focus now is on improving elbows, eyes, and hearts in terms of health testing. For example, many of the top stud dogs out there have a grade II dysplastic elbow, but only one of the elbows, while the other is normal. Again, this raises the controversial question of: does that make it genetic, or an injury when young? That is one area of controversy that will not easily go away, as there are no obvious, definitive answers to the question. Given many well educated, ethical, successful breeders continue to use those dogs to enhance their programs, we suspect most are agreeing with the latter. A big issue in the breed right now is eye testing. Many of the dogs initially pass their CERF exams, and only years later, then have junior cataracts show up. They can initially show up, go away for years, then show up again later in life. This is another big issue, as many people cannot even agree as to whether "junior cataracts" are genetic in origin, and they have no functional impact on eye sight. But in the end, the dogs with these issues are still being used, and producing large numbers of offspring, because they consistently produce what people what out of them, while other dogs that do not demonstrate the same issues, cannot consistently produce high quality offspring. Even if they do, nobody can ever say for sure what health issues will suddenly "pop" out of those lines some number of years down the road.
It is in these kinds of situations that ethical breeders have to face on a regular basis when making educated, ethical breeding decisions. To our way of thinking, as nobody in the dog world will ever agree on this issue, it really comes down to open and honest "disclosure." If you make the choice to breed a dog with great traits in a well planned out attempt to better the breed with the potential offspring, but that dog has an issue passing some kind of a health test (as long as it is not DJD or something that severely impacts health in nature), as long as a breeder is fully open to buyers about the issues at hand, the reasons for that breeding decision, and the increased potential for potential issues in the puppies, if any....is that unethical? We would say "no," as long as there is full disclosure and strong guarantees/refund policies in place in the puppy contracts. But again, that is just our opinion, and it is a complicated issue.
I hope that information helps more than confuses.....and again, it is just our opinion.
Betty and Byron Osing