Dysplasia - Genetics or Environment? - Page 1

Question for the breeders... in your opinion, what are the most important factors to reduce the incidence of hip dysplasia? How much does heredity affect the outcome vs. the environmental factors such as diet, weight, supplements, etc.? I'm only asking for opinions, and I'm not out to prove anything, so let's keep it civil. The reason I ask is because I'm surprised to find a disconnect between some breeders and the hip stat registries: OFA and PennHIP. On the OFA web site, they state that HD is a genetic defect that can, and does, get passed on from parents to pups. Furthermore, they state that environmental factors such as diet, supplements, and even weight have only secondary effects, or that they affect the symptoms fo HD, or the time of onset of symptoms. On the PennHIP web site, they state that hip subluxation is the primary factor to predict which dogs will become dysplastic. Furthermore, it is also breed specific. For example, a GSD with the same laxity as a Golden Retriever is more likely to develop HD. I find it odd that I can't find any reference on either site to guidelines for diet, exercise, weight control, etc., considering how much emphasis is put on environmental factors by many breeders. To be sure, I firmly believe that a quality diet, good exercse, and proper weight control are essential to the health and vitality of any working dog. But how strongly are these related to HD? I've encountered now several breeders that state that HD is mostly influenced by these environmental factors, and not genetics, which therefore abicates them at least partially from the responsibility for producing pups with bad hips. The onus is thus shifted to the puppy owner if diet, exercise, weight and the like are truly the "cause" of HD. I'm not saying this is "correct", nor am I saying that this is "wrong" thinking. However, this does beg the question... if environmental factors are the primary contributors to the incidence of HD in the GSD, then why is this never acknowledged by OFA or PennHIP? Considering that both these groups state their mission is to help reduce or eliminate this painful, debilitating condition by educating the public? Please share your opinions. You can send me a PM or an email if you prefer to not post. Yvette

Helo Yvette, Like Human Medicines There Is Little Or No Monetary Reward For Curing The Problems. I Do Agree That Diet Is Far More Important Than The Lack Of Onus That The OFA Or Pennhip Put Upon It. Hence The Saying "We Are What We Eat" ! Stem Cell research Could Be The Ultimate Answer Here. Truly, Thomas

Opinions have a way of being more popular when they coincide with the interests of the parties involved. Breeders would like to hope that environment, diet and exercise play a greater part. OFA has more to gain if the belief is leaning towards genetics. Obesity would be a good comparison example to HD; "Genetically predisposed, but environmentally engendered." How much overall is probably your question, but the portions are probably more variable for each individual dog. A dog may be 10% genetically inclined to show symptoms, but 70% more because of continuous stress from a improper activity while young and the bones are still forming. On the other hand a dog 70% inclined to acquire HD from its genetic predisposition, with moderate activity and healthy diet, have no environmental contributors that reveal sypmtoms of HD, or perhaps until very much older. Aside from pedigree (and near-family) research on hip stats for the hereditable aspect, if you're a breeder there's not alot you can do for what "isn't genetic", but to educate your clients about what environmental causes can contribute to HD. Some breeders put clauses in their contracts for acceptable diets, and receipts would be proof for following them.

Hello, we do some breeding and our policy tries to emulate current statistics. HD is very high in the gsd breed. We have read studies saying Vit. C in a diet can decrease incidence by up to 10%; low impact excersize can decrease incidence; Glucosamine can reduce incidence by 10%. Huge factor is weight. Study done on large breed puppies showed a 50% ! increase in HD by 6 months in group given free choice feeding (pups were clinically obese- which is defined as 10& over ideal weight). I have also read 90% of HD is environmental- that is huge and i am not sure how accurate; but it strongly suggests placing emphasis on puppy rearing techniques. Ok, so not all statistical studies are accurate, nor can the results be reliably duplicated. BUT, as a breeder we take 100% responsibility on selecting dogs with clear xrays, try to maintain good hip ratings for at least three generations-(as well as all dogs in 7 gen. pedigree with xrays certification), we look at siblings and relatives hip production records also, and feed puppies optimal RAW diets. We keep the pups round but not heavy. The RAW diet gives the pups nice large, clean, square joints, very shiny coats (40% fat) and they do not get that roly poly look of loose skin and wobbly fat you see frequently. Ears come up quickly and firmly. We DO however have a clause in our sales contract that if the buyer allows pup to become clinically obese in the first year of life (we do require vet exams) the hip guarantee is null and void. We feel if the buyer should makes a conscientious choice to try to mitigate causative factors; it is a team approach. We also include a diet plan in the sales contract. Bottom line: Team approach with science to support ideas. Responsibility lies with buyer and breeder equally i believe. HD is terrible and worth putting allot of effort into avoiding. cindy g

@darylehret: I think I agree with you. The drift is going so: before 20 years people spoke about 50%/50% - today the trend is 30% genetics/70% how growing up puppies. I tend to say 30% is genetic - the rest is false imposition, false weight, false food. My family were old breeders ( before 30 years or much more ) of another breed. They haven¿t had so much HD like today. A law was altough to x-rayed parents. But there was not a difference between a/a1/a2/ ect. - only HD or not HD. In that time they haven¿t had "instant food" like dry food. Most they feed there puppies with fresh meat from cows, with fresh vegetables, with some vitamins and calcium every day. They haven¿t had some problem with HD although it was a problem of that race. Today I¿ve heard: no calcium because not good for bones - yes: calcium should be actually baneful. A little bewildering. I think - the first and most important thing to breed is to have parents WITHOUT any clinical findings of HD ( = a ). The second thing is - what the pregnant mother get to eat, than the puppies what they eat - beginning from their first day. Additionally to give them all what they need for normal action to create athletic muscles - and not to much of food, more fewer, often and rich in content. The action is for me the most important thing - run, but not jump - and never on the bottom from concrete, only in free nature - gras is soft - for the small sensitive bones and tendons. An owner with endurance to wait with a lot of train until the puppies are full-grown. No running with the bike before 1 year... and a lot of other things. The young dog needs time for his healthy development - that time what the most owners miss.

I personally think that initial hip quality (not dysplasie) is 100% genetic. What progressively happens to this inherited hip quality is determined by the combination of quality, muscle mass, environment. Muscle mass (and the resulting "tightness" of the joint) determines how much a joint can separate (flaot) from its ideal position. If the joint has great capacity (say, an O.F.A. Excellent or Good) then the muscle mass is perhaps not so important as there is sufficient bone mass to share the load. However if the joint has minimal capacity (say, an O.F.A. Fair) then it relies very much on the muscle mass to bind it in place and prevent displacement, which in turn causes scarring that appears as arthritis. So, what is the ratio of heridability vs. environment? I think that is determined first by the initial hip joint quality, second by the muscle mass present, and third by the environment itself. In other words, I would expect a puppy born with O.F.A Excellent to Good hip quality to remain very near that when examined at twenty-four (24) months of age, provided the muscle mass is at least normal. For the puppy born with O.F.A. Fair hip quality I would expect this puppy to be a crapshoot unless he was raised carefully. In essence, I believe that when we begin with higher hip quality that we are more apt to maintain higher hip quality and life for the puppy is more forgiving. These are just my opinions and based much more on engineering rather than biological thoughts. I do not think there is a true heridability vs. environment ratio that can be mathmatically proven as there are few controls and too many variables. I think we should all be careful with a developing puppy, regardless of his initial hip quality. Regards, Bob-O

I think you're absolutely right about what really matters from a breeder's standpoint; the heritability. The fact that some breeds suffer more than others is proof enough in my eyes. The difficulty being that with the polygenic nature of "hip quality", certifications such as PennHip, OFA, etc. cannot reveal a completely accurate portrayal for heritable transfer. Families and parental phenotypes and production stats are the best proofing we have. If heritability is low, it can be assumed that evironment plays a lesser part.

Quote from a translated German webpage: 12-12-2007 Environmental factors such as feeding, posture and movement / load can affect the expression of the HD for genetically contaminated animals, BUT! Without hereditary disposition occurs this disease did not occur. Recent molecular genetic research at the University of Hanover come to the conclusion that the heritability of hip dysplasia 90%. http://www.bloggen.be/hd/archief.php?ID=117 Also on this page, in the menu bar can be found some statistical compilations on the HD production stats of top stud producers and best producing kennels in XLS file format.

It should be the first idea of every breeder to take parents without any clinical findings of HD. The thing is that everyone can do what he want to do. It is in only his responsibility to use healthy parents. And there are enough healthy parents. Last but not least: the responsibility of the breeder and his ideas to get more healthy puppies..... But nobody - no enthusiast and no serious breeder- can give a guarantee.