HD questions - Page 2

Agree 100% with Preston and would only add that it is also good to know the hips status of the siblings of the dogs in your pedigrees and what they have produced. I would never use the only clear dog from a litter of dysplastics or a normal dog with a severely dysplastic littermate. NZ's are not breeding material for me and yes, I know  about Jeck, the one dog in a million. What I never hear about Jeck is - what % of normal hips his offspring produced and how many of his progent and theri progeny were actually xrayed. Are those stats available? BTW the OFA rating is only as good as the xray. Sometimes the only difference between a good and a fair, etc is the skill of the techs takiing the xray and the quality of the film.

Two questions here:  Can we eliminate HD by breeding only OFA Good or Excellent dogs (or equivalent)?  I do not think it is possible to completely wipe out HD but that definately would be a step in the right direction.  There are so many good dogs available in the US, it seems plausible that breeders could be selective in such a manner.

Next question:  How to "prove" what a dog produces, regardless of his/her own hip rating?  The only way I see to answer this with confidence is to do statistical analysis, and have access to lots and lots of data.  Unfortunately with OFA you don't get to see the results of all X-rays.  Once the films are taken, the owner can choose to NOT send in the X-rays if they look bad.  So, the OFA database is missing some data on the low end.  Also, since all dogs do not get X-rayed at all, much of the dataset for any breed is mssing.

I'm an engineer, and because I'm such a geek (and darn proud of it) I did a statistical analysis of the OFA hip and elbow ratings for the dogs out of Chip Weiss' kennel, because he's the breeder of my pup.  The overall picture was very good, and his dogs have produced results that are statistically better than the baseline population of GSD's.  However, it is difficult to draw decisive conclusions on any individual dogs because the data set is small relative to the population.  For example, my dog's dam has never produced any registered OFA dog that is not OFA Good on hips, and Normal elbows.  Is this "proof" that she will never produce a dysplastic dog, or an OFA Excellent?  Hmmm.. no.

Furthermore, an analysis of OFA ratings is complicated by the fact that the data is categorical.  There is no distinction withing each category.  A dog that barely makes OFA Good is still Good.  A dog that is just shy of Excellent is also still just Good.  Doing statistical analysis of categorical data is always more difficult than working with "continuous" data.

I've been watching the developments on the PennHIP method with much interest because they provide results on a "continuous" scale instead of lumping results into discrete categories.  However, this a new method and I do not know how to get access to data myself, and the published papers show the results of the analysis, not the raw data so I cannot duplicate their analysis.

Geez... I've probably lost half my audience with this techno-babble.  My apologies!  Nevertheless, if anyone has some hip/elbow data available and they would like a statiscal analysis done, I would happy to do this.  I would love a chance to practice on a larger data set.

Yvette

The OFA results, A-Stamp results are only as good as the people taking the films and the dog owners.  Had some hip/elbow films taken that "vanished" and never were recovered.   The X-rays were to be submitted to OFA by the vet office.  I never got to see them and was just told the dog would OFA.  Yes, I got a credit for the x-rays.  LOL. No, I never had them redone as the dog already had her Hips A-Normal and Elbows Normal.  I just wanted the OFA hip/elbow results for the US born litter as the sire was also ofa'd.

off topic, but Sue where do you get the frozen lamb/venison necks? Is the venison tested for Mad Cow? We feed organic chicken necks but it would be nice to diversify.

cindy

Here is a link to my supplier:  http://k9rawdiet.com/Whole-Bones-c-17.html

Everything is human grade.  I get all different kinds of whole bones from them & I also get  their blends.  I like it because everything they sell is hormone & antibiotic free, PLUS they deliver to my door!

gieske,

Very few places test all animals for BSE (mad cow).  A couple companies want to test everything and are running into roadblocks, the other companies want to do the random testing and don't want anybody doing more.  I don't know of any company testing anything except beef for BSE though some states have guidelines in place for wild game transport due to the similar disease showing up in game animals.

Does anyone know if the ZW system in Germany is actually improving hip production? I know it has its flaws but is it helping

Also, has anyone seen a litter from two ofa excellent parents produce bad hips? Curiousity

Do right, market/economic, psychological and political realities will likely prevent an SV commitment to raise the bar on hip certification stamps to a two year minimum.  However, a dedicated breeder can do this himself(herself) if motivated enough and willing to spend a great deal of time researching breeding choices.  I define disabling HD as any habitual or periodic limping or weakness in one or both hips usually accompanied by some periodic difficulty getting up from a down position. In the vast majority of cases this will never happen with OFA fair, good or excellent (especially in any norberg angle of 115 degrees).  Any GSD with shallow and OFA fair hips should be kept in trim and good conditiion to prevent excess stress on these shallow but clean joints. A significant number of "a normals" (one year xrays) turn out later to be slightly displastic and will not OFA at even the fair level.  I especially admire the American and Canadian breeders who use SV or European type bloodlines and choose to impose higher standards for hips on their GSDs (over and above the SV one year rating), choosing to use the OFA hip system based on two years old.  There are a number of these kennels and they deserve great respect and admiration.  These breeders really care about producing GSDs with clean hips and are a breath of fresh air.  Hat's off to all of them. 

Thanks Preston.  I find very interesting your comment about the a1's sometimes not qualifying under the OFA way, because of the difference between when they are done.  SV being done at one year of age and OFA  being done after two years of age.  So, if I purchase an import that has a Sch II title and is HD rated at a1, I could possibly bring it to the U. S. and have it OFA'ed and find out that it is "mildly HD" and have a choice of breeding it and just telling people that it was rated as "a1" or not breeding it at all.

It really is a crap shoot when buying an import, apparently.  Unless you condition the purchase on the dog passing an OFA test.  But then there are the elbows.  What a tough game.

This is a great thread.  I offer these questions out for your consideration.

1.  A wolfpack can be genetic fishbowl for many generations since typically only the Alpha M and F will mate.  Therefore the progeny are normally closely related yet genetic faults are at a minimum.....why would this be good/bad for dogs.

2.  I have read that the most inbred breed of dog are the "wild" dogs/Dingos in Australia......they seem healthy enough to thrive.

So how much linebreeding is too much and how much crossbreeding is too little?  I look forward to the free education.