an interesting thread ....and it highlights how 'breeding by numbers' simply cannot work - you cannot only breed according to health test results ...or COI's.. or indeed show wins .....you must look at the whole package and that's what many find difficult to understand - nature is never black and white and by concentrating on eliminating one 'problem' she'll throw another into the pool.

The most important tool any breeder has is their breed knowledge - this includes health test results but also knowledge of the dogs that are behind their pedigrees -knowledge such as which dogs passed on poor temperaments .....had reproduction problems.....produced epilepsy ...passed on poor construction or bad bites - none of these things are testable ...all are important....and the joker in the pack is that if you do find dogs that 'have it all' you have to be very careful not to flood your breed with their genes - we must also take the long term view and make breedung decisions that are sustainable for our breeds in the future.

Breeders get a lot of flack from those that wish them to take the 'no brainer' route of eliminating from their gene pools all dogs that are carriers or have less than perfect test results ..but that's the quickest way to the the destruction of our breeds - we must ALWAYS look at the whole picture before we make our choices.

I keep thinking I'm not destined to post to this thread as every time I try SOMETHING comes up.

There are ethics questions at every turn.

Wow, we are actually on the same wavelength

It has always worried me that so many breeders that health test find some excuse as to why they should discount the results. And yes, I do understand that a carrier can only produce PRA if mated to either another carrier or an affected dog (in which case it could produce it without bringing the carrier into the equation). But the truth is a huge amount of breeders do not health test so could buy a puppy from this wonderful carrier that just HAS to be bred from and get mated to another carrier. And I wonder where the PRA that appears from nowhere will be blamed on

I am also very confused about HD. Surely, whatever the score, if the dog has any sign of HD then it can pass it on. So a bitch or dog with a low score are not going to necessarily produce puppies that do not suffer badly with HD. The puppies that inherit the right genes will be predisposed to HD and could get it very badly. Hip scoring has been happening for 35ish years, surely in that time it could have been bred out of at least some of the breeds - but in fact it started appearing in breeds, such as the border collie, who had never suffered with it before. So surely it is just the same as the debate over pra carriers - if they have HD, albeit a low score, then they are adding to the problem when bred from.

WHO is saying discount the results? Work with them, outside extremes, they are tools to make breeding decisions, NOT discount them. I didn't breed from my bitch because she her hipscore was too high - SIMPLES - but within boundaries and working around averages, they are there to work WITH.

ALL breed averages are falling, and many have fallen considerably in the last 5 years which is why the KC now public 5 year rolling averages.

You cannot erradicate HD using hipscoring - what you can do is significantly reduce risk of problems with the progeny. We also know that environmental factors do play a role in the effect on both hips and elbows - which is why it is so important that new owners are given good exercise and dietary advice particularly during the first 12 months of a dogs life.

Historically, many many thousands of records show us there is a correlation between average to low scoring parents and their progeny - statisically - the risks rise considerably of producing offspring with hip problems if you use two severely dysplastic dogs, the same is not found when using two parents with low levels of dysplasia.

Your comments sound more like an argument not to use the schemes rather than to work with results as HD can often be asymptomatic - there is no excuse for not using it in affected breeders, because the progeny (and their poor owners) may not be as lucky

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What you need to know before buying a Labrador puppy

No, I am not saying you should not use the schemes. But I have been involved in dogs since before there were any schemes, and I was amazed at the number of people that tested various breeds and then said the results did not matter as they did not really apply to their sex or whatever!

I dont disbelieve you over HD results but I still dont understand it. Also is the environmental infuence on HD only going to show it up in dogs from parents with a score which means they will have passed it on even if they have a fairly insignificant score themselves. Just a question, not a statement.
I have some knowledge of genetics but nothing very advanced and I cannot see how a gene for a disease or disability can be graded. Either they have it or they do not surely and so the pups are going to inherit the gene even if they do not actually get HD. Maybe I am simplifying if too much but that is how I have always seen it.

Now, I know very little about all this, so I am sure swarthy will come and clarify very shortly, but I always thought there is an environmental component with HD. The amount of people I see in the park that walk their Lab puppies for 3 hours a day and are then surprised that they develop problems is quite astounding.

Keep it going, guys. This thread is fascinating!

Statistically - a small proportiion of pups could go on to have poor hips, hence why we say "reduce risk" rather than remove it - you cannot guarantee against it and I make this clear to my puppy buyers in writing.

What is becoming increasingly clear in many circles (and this is anecdotal but fairly comprehensive) is that where pups from low scoring parents go on to have bad hips - often - the only ones who ever know about it is the ones who actually go for hip scoring - i.e. asymptomatic.

We hear a very different story where people have bought 'bargain basement' pups - where most of the dogs affected go on to have quite serious problems.

Now bear in mind - with BB pups, we have no idea of knowing what their parents hips are like - they could be perfect, they could be off the scale ( but more than likely somewhere inbetween the two)

In addition, many breeders who don't health test cut corners in other ways - feeding mum, raising the pups etc etc

This lack of knowledge also often follows through to not giving good exercise and diet advice for the first 12 months of the pups life.

In the absence of a DNA test (which we may never see in our lifetime), there is no way of knowing more than we already know but history has shown us, the likelihood of problems developing in pups from low scoring parents is significantlly lower - and this is backed up in the statistics which show marginally lower averages in their progeny than those pups from higher and unscored parents.

My own girl - there was absolutely nothing in her lines to suggest she would develop hip problems - until we took her for plates chances are, her progeny would have been fine with the right dog, but I wasn't prepared to take that risk.

I adhered to EVERYTHING I should have with her in the first 12 months, so you can imagine I was devastated - there again - had I not done the 'right' thing - those s****y scores could have turned into full blown dysplasia - rather than something we know is there but actually presents no manifestation of problems and has seen her do very well in the showring until she had an accident and damaged another part of her legs (nothing to do with her hips). She is 6 now and still the first "to be there" every time, although my new baby is giving her a run for her money

ETA - it was my own experiences that led me to buy the hipscoring database and start studying this and analysing the stats in more depth.

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What you need to know before buying a Labrador puppy

Yes . . . . . you are simplifying it too much.

HD is not a condition caused by 'a gene'. It is not one about which anyone can say 'they either have it or they don't'.

Wish it was as it would be sorted by now if that was the case.

By all evidence it is a polygenetic threshold trait . . . on many genes from which the wrong number and combination, along with environmental factors, can cause the condition.

So . . . . if the sire has mostly all the right genes, and a few that are implicated with HD, and the dam also has mostly all the right genes, and a few that are implicatd with HD, then both of those dogs will test 'good'.

Some of their pups will also inherit mostly all the right genes, and most likely test 'good'.

Unfortunately others, by luck of the draw, will inherit more of the 'implicated' genes from both sire and dam and less of the 'good'. Couple this with poor environmental conditions, and they will probably end up with HD.

To make it more complicated, some of the 'implicated' genes that, when added up, predispose to HD . . . might be beneficial with regard to other conditions.

That is my simplified explanation of how HD works, anyway. If I have confused anyone, the link below might explain better than I.

I have had reason to learn of this type of inheritance only as it affects me and mine very closely. We are, in fact, cursed 'carriers'. My own mother died after suffering 35 years with an eventually torturous condition (early onset Parkinson's) that (we now know) was probably passed along the same way - many genes and the environment contributed. My brother is into his fifteenth year down the same road. Much to our relief we also now know where their environmental triggers entered their system and what some of them were. I say that as the rest of her children, and our children, are all at risk genetically . . . . but we are relieved to at least have a hint about what to avoid in our environment.

I wouldn't have been inspired to delve into genetics if this was not the case. Our blessings in life come from odd places sometimes.

Hip Dysplasia as an example of a Polygenic Disorder,Breeding Bull Terriers,Breeding Bull Terriers,Pedigree Analysis,Genetic Diversity, Health Concerns, Managing Genetic Disorders,Hip Dysplasia, bullterrierz.com

CC--Happy Birthday to my mom.

Thanks for posting that CC - I actually had something in my last post on the speed of bone growth misaligning to cause joint problems and then removed it - because of the very little knowledge I do have - I understood that this could happen with elbows, but wasn't so sure it could happen with hips - this article intimates it can.

"We know that rapid weight gain at an early age can produce “sloppy” hips; where the maturation of the ligament and muscle components does not keep up with bone growth. By switching from puppy food to adult food after 14 weeks of age, or using large breed puppy food, dogs grow at a slower, and more uniform rate. The adult size and stature of a dog is genetically predetermined. How fast a dog reaches its adult size can influence the expression of hip dysplasia. "

This re-enforces what many of us have been saying for a long time (I've never seen this particular article) about diet - although the age indicated here for switching to adult food is pretty much half that again that this suggests - and there may be an additional reason for that - because the quantities you give such a young pup are high - it presents with a converse risk of them ingesting more calcium than by remaining with puppy foods - which similarly to protein, can also affect bone growth and joint formation.

The trouble is however, to site my own circumstances - this article very clearly suggests that one part of a pairing can be hip improvers - and indeed, I know from studying the database that there are dogs who consistently produce lower hips whatever they are bred to even if their own hips aren't perfect . Interestingly - many of these dogs come from the same lines - suggesting quite clearly that when a random very high score may appear in an otherwise history of low scored progeny - it's the pairing as opposed to the individual dog - and in certain dogs, we are seeing consistently low scores and high levels of 0/0 scoring dogs out of many differently bred bitches

So many people are drummed into breed averages - it then can raise eyebrowse when a higher than usual parent is used, even if the dog has that many other qualities you wish to retain in a breed - even though we know through history that many of these dogs never go on to produce problematic offspring, either visually, or through hipscoring.

In some ways I wish I had seen that article sooner, in others I am so very glad i didn't - but it does re-enforce at least in part the belief I formed from the research I did.

======================

As for the recent study I read on PennHip - it's sample study didn't re-enforce the findings on the radio-graphs, with only one of the dogs in the higher centile range, going on to actually develop later onset OA (which is what the PennHip method evaluates and certainly not a tool to be ignored) - but overall, is that as comprehensive as the UK method which evaluates all elements of the hip - we look at overall scores as a measure, but the breakdown covers many parts of the hip, just one of which is joint laxity.

It's not saying the principle isn't correct - but it does need very large sample sizes to be measured over long periods of time in order to validate it's hypothesis - is this feasible / practical etc?

Someone recently posted that an orthopaedic specialist told her that hips degenerate as they get older (which of course, the PennHipp methods says isn't accurate - as it depends on the level of joint laxicity whether the dog will go on to develop OA or not - and I've always seen the mid to late onset of OA to be very different to OA - which of course it is and it isn't - because poor joints will usually be subject to more stress over time, and therefore deteriorate quicker - but then the dog who receives uniformed structured exercise, can also develop muscle mass which protects those joints, enabling them to live a long, happy and healthy life free of visible OA.

UK records very clearly show us, particularly in the early days of the scheme, that dogs were presenting with PERFECT and damn near perfect hips at 8/9/10 years old - so one would assume that if these dogs had been played young under the PH method, their Joint Laxicity would have been below 0.3.

Had we known then what we know now - coupled with knowing what these same dogs produced in terms of progeny, their stored semen could have potentially had an invaluable impact on their breeds further down the line - and been particularly invaluable in not only reducing high breed averages, but also in allowing worthy dogs with much poorer hips to remain in the gene pool - now that IS selective breeding.

However, in most gene pools, there should be sufficient breadth of types to find a dog that complements the bitch in many characteristcs without compromising the quality of the progeny whilst simultaneously ensuring progeny have a very high chance of having superior hips to the bitch with high hips (obviously - we have to focus on the influence of the dog over the bitch as they have the far greater propensity to longevity even after their death, whereas a bitch has just a few years when she can produce progeny, and even then, those numbers will be limited.

Interestingly, this is borne out in the historical hipscoring database which shows, that up to a point, progeny will ALWAYS present with scores lower than their parents - whereas when we get to the lower end of the scale - low scoring progeny may often produce progeny scoring higher than themselves, but below published breed averages.

Very interesting - thanks

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What you need to know before buying a Labrador puppy