Hips and Hip "guarantees"

[Sarah'sSita]

I was surfing around and looking at some breeders' online purchase guarantees and contracts. One I found stated that Canine Hip Dysplasia is 25% genetic and 75% environment. However there was no citations as to the source of that information or its validity. Seems like an "out" for the breeder if the dog doesn't pass OFA at 2 years. My understanding, is that severe debilitating HD is largely genetic. But I do not know where that info came from-a particular study? Of note there were no OFA listed for the Dam or Sire of this litter. Infact not even a pedigree link (they are asking $2K per pup!) However that is not my question...what is the latest data known about CHD and is it common to have such an explanation in a contract and guarantee?

[JKlatsky]

It's interesting. I've heard of 3 basic theories to CHD- Genetics, Environment, and Dietary Deficiency.

Of all the breeders I know...it seems to depend on what theory they subscribe to (and there seem to be devotees of all) as to what they put in their contracts.

We all know that early repetitive exercise (jogging on pavement, running stairs, heavy jumping, etc.) is not great for our puppies joints but a lot of people don't know. Often times breeders I've known put this into their contract to make people aware of the damage they can do to their puppies and to attach some monetary penalty to make the information sink in. I've never known one of these breeders to say "Sorry, the HD is your fault" and NOT take the puppy back. They still honor the guarantee.

It is not uncommon for people who subscribe to the Vitamin C theory to require supplementation as a stipulation in their guarantee. I have the link for that... http://www.belfield.com/pdfs/Hip_dysplasia.pdf

[Liesje]

I've always wondered, does "genetic" mean "got it from the parent(s)" or simply that they are "born with it"? Does the question make sense? I mean sometimes it just seems so random that I wonder if more dogs are just "born with it" (or the predisposition) rather than actually inheriting it from the parents. Like, a bunch of dogs will be fine and then one dog in the litter is crippled. But I would hope it's more "got it from the parent(s)" because that would seem easier to isolate and predict with more research.

[gagsd]

Not a biologist, but genetic would be "got from parents" and congenital would be "born with it"----- I think!

From what I have read and discussed with my vet, genetics may set the stage, but environmental factors have a huge influence on how the HD shows itself. I doubt there are any studies that can show definitive percentages.

[selzer]

Well they say it is polygenic. So it does not necessarily follow from the parents, but it is almost hit and miss. So it may skip a generation or two.

Others say that 25% of puppies end up with it. I don't know. So far I have lucked out with the five bitches I have out of Arwen and Dubya.

Hip dysplasia is really throughout the breed. Is it worse in the American showlines where people have bred for extreme slopes or where pups are inbred closely? Is it worse in the BYB lines where dogs that have not been screened are bred indiscriminately and possibly closely inbred? It is worse in the working lines where the straighter backs, etc. Is it less likely in imported dogs that have been a-stamped all the way back? Is it less likely out of parents that have good or excellent hips?

I guess there are as many theories as there are breeders.

I think that some dogs are born with a propensity toward poor hips, but the risk of having certifiably bad hips can be reduced by keeping the animal at the ideal weight, not overdoing calcium, not requiring the puppy to excersize with high impact or harsh repetition, but to allow puppies to be puppies and exersize as much as they will.

I also think that as much as is possible, we should not breed dogs that have hip dysplasia, or those that produce bad hips.

[BlackGSD]

Originally Posted By: Sarah'sSita One I found stated that Canine Hip Dysplasia is 25% genetic and 75% environment.

If this were the case, how is it that there are dogs that eat the cheapest junk kibble, do all of the "no-no's" as puppies and STILL end up with good hips. And there are others that eat only the "best" food, and do NO running, jumping, ect... as puppies and STILL end up with terrible hips?

[pupresq]

Genetic means it was transmitted via the DNA, encoded in the genetics of that dog, inherited - so yes, "got it from the parents," but not to be confused with, say, a behavioral attribute that a puppy picked up from its mother by observation. Congenital means present at birth, so it can apply to a genetic problem but also something that occured in utero, developmentally etc. Some birth defects are a result of a genetic problem but others occur during development, either is congenital.

My understanding of HD is that it's poygenic, as Selzer says, which means it's not inherited in the very straight forward Mendelian manner that most people are familiar with. This is one of the things that makes it so tough to eliminate. It's also not a binary issue - where a dog has it or they don't, clearly there are all sorts of degrees of joint malformation.

While diet and exercise are potentially important in the expression of HD in an individual dog, the underlying malformation is genetic. Diet and exercise can't cure a dog of HD if it's present nor can poor diet or exercise create HD in a dog that doesn't have it.

I would guess the site in the OP's post is trying to make excuses for not OFA certifying their breeding stock.

[Doc]

Originally Posted By: pupresqGenetic means it was transmitted via the DNA, encoded in the genetics of that dog, inherited - so yes, "got it from the parents," but not to be confused with, say, a behavioral attribute that a puppy picked up from its mother by observation. Congenital means present at birth, so it can apply to a genetic problem but also something that occured in utero, developmentally etc. Some birth defects are a result of a genetic problem but others occur during development, either is congenital.

My understanding of HD is that it's poygenic, as Selzer says, which means it's not inherited in the very straight forward Mendelian manner that most people are familiar with. This is one of the things that makes it so tough to eliminate. It's also not a binary issue - where a dog has it or they don't, clearly there are all sorts of degrees of joint malformation.

While diet and exercise are potentially important in the expression of HD in an individual dog, the underlying malformation is genetic. Diet and exercise can't cure a dog of HD if it's present nor can poor diet or exercise create HD in a dog that doesn't have it.

I would guess the site in the OP's post is trying to make excuses for not OFA certifying their breeding stock.

Your statement that diet and nutrition can not positively correct HD is false. For 50 + years all we heard is that HD is polygenetic. And that was preached 50 years and no questioned it. After 50+ years of trying to eliminate HD through breeding, we are no closer now than we were then. I think the original hypothesis is wrong - Genetics may only be one element of the HD puzzle. If it is genetic, then if a one pup in a litter gets HD, all of that litter should not be allowed to breed and the parents that produced that litter should not breed again. We all know that will never happen.

Diet should and must be addressed in the same light as the genetic cause. 37 litters of German shepherds, some from HD parents, have been produced with NO HD in a single pup. How? Supplimenting both the bitch and pups with high doses of Vitamin C (see Belfield's articles). And you say diet can't help? I think this information is as valid if not more than the polygenetic one. So I think the role of proper nutrition must be addressed by the breeder and buyer of pups.

Proper exercise is also very important. Swimming can positively impact a dog and what the hips look like in an x-ray I've heard of breeders not x-raying their stock until they have had weeks of exercise and in particular - swimming everyday.

HD is just one of many health issues surrounding the German shepherd. It does seem to be the one that gets a great deal of attention whereas other deadly issues are overlooked. There is no easy answer concerning the causes of HD, but as a breeder, I address every aspect with great concern.

[pupresq]

Quote: Your statement that diet and nutrition can not impact HD is false.

You need to re-read my post. I didn't say that diet and nutrition had no impact on HD or couldn't help. I said that diet and nutrition couldn't make a dysplastic dog have normal hips or a non-dysplastic dog have abnormal hips. But I clearly said that they DO have an impact on expression.

Quote: If it is genetic, then if a one pup in a litter gets HD, all of that litter should not be allowed to breed and the parents that produced that litter should not breed again.

That doesn't actually logically follow. If getting rid of HD is the only thing you're breeding for them maybe, but as it's just one part of the GSD puzzle.

As to whether HD is actually caused by or can be cured by nutrition and diet, I'd want to see studies before jumping on that bandwagon. I'm not saying it's impossible, but my post reflected what I think is currently supported by the science. If that's not correct, please post links (and not anecdotal links - real studies with controls etc).

[pupresq]

Here's an article that discusses the interplay between genetics and nutrition in terms of phenotypic expression of the underlying genetic disorder:

http://www.woodhavenlabs.com/chd2.html

Their conclusion:

Quote:Conclusions: While environmental effects, to include nutrition and exercise, may play a part in mitigating or delaying the onset of clinical signs and clinical symptoms hip dysplasia remains a genetically transmitted disease. Only by rigorous genetic selection will the incidence rate be reduced. In the meantime, it makes sense to have lean puppies that are exercised regularly and to avoid breeding any animals from litters that showed signs of hip dysplasia. It is probable that even normal exercise levels may increase the phenotypic expression of CHD of a genetically predisposed dog. Stay away from calcium supplementation of any kind; all it can do is hurt. There is no conclusive evidence tat vitamin C can prevent hip dysplasia, but there is some evidence that vitamin C may be useful in reducing pain and inflammation in the dysplastic dog. Let your conscience and your veterinarian be your guides in supplementing with vitamin C. Fortunately, large doses of vitamin C are readily excreted, but it is still possible to cause untoward side effects with megadoses.