I did prelims on my 6 month old. The reason for doing prelims early is because I have had elbow issues with males I have purchased before and didn't want to wait until he turned two to find out he had a problem, I had almost finished a championship on the previous male I had.
This is a male that I bred. Elbows have come back good, but the hips have been rated as "fair". Is this something that is likely to improve with time? Is this boy going to be a keeper??

Hard to say. Trying to determine the adult orthopedic status of a six month old puppy is looking into a crystal ball. There are so many growth spurts and changes that occur over the next 12-18 months that it would be nearly impossible to predict the final outcome.
It would be similar to looking at a 2-3 year old child's baby teeth and ordering their teenager braces.

OFA hip evaluations overall at six months have almost no correlation with OFA hip evaluations at 24 months.

If you are concerned, you can get a PennHIP evaluation. Last time I looked the correlation between six month evaluations and 2 year evaluations was about 85%.

These are general statistical statements. Statistics are about general populations and say nothing about your particular dog.

Kate- where have you found information that supports 6mo OFA hip ratings have "almost no correlation" with final ratings? I know a number of vets/radiologists who would disagree with you. They are quick to state that an elbow can change, but hips that look good at that age are a pretty safe bet to look good at two.

I am on the same page with Nicole. I do think alot of elbows abnormalities do not show up in the rads until the dog is older...unless they are severe. I try not to do prelims until at least 12 mos...even then they can change.

A better question is where have you found the data and statistical analysis to support that a correlation exists between 6-month and 2-year hip evaluation? The way science works is that you assume no correlation until you can demonstrate statistically that a correlation exists.

If a correlation existed, then OFA would be telling you what the correlation was and would be telling you how much weight to place on a 6-month evaluation.

Fair IS passing. If there are other things wrong with the dog, or you would prefer to go on to another dog, then fine, place him now before you are too invested. Can a FAIR change? Sure it can. Can it stay the same? You bet! I recently bred to a beautiful OFA FAIR dog. I am confident in my bitches lines and what this dog has thrown.

How do you know the vet techs pulled the legs enough to get the proper placement on the hip joints? Maybe the dog shifted just at the last second...who knows.

I like the crystal ball analogy. There is no way to tell. If you like him, take a chance on him.

I'll go with the experience of the vets I work with over your assumptions ;)

A better question? Can you please answer the question?

OFA says....
The use of preliminary radiographs as early as 4 months of age can be used by breeders to add valuable information on the hip status of dogs they choose to use in a breeding program.
http://www.offa.org/hd_guidelines.html

I must say that the OFA website has some fancy footwork demonstrating something called "reliability" between early evaluations and 2 year evaluations. I can't even figure out what the word "reliability" means in this context nor how it applies to statistical demonstration of correlation and predictive validity. According to this an OFA excellent could turn out to be OFA fair and they would still call the first evaluation "reliable."

Nicole, lack of correlation is not "my" assumption; it is the assumption used in scientific method. Until there is a scientific demonstration of correlation, no correlation is presumed to exist. It's just how science works and how tests are evaluated scientifically. If you have faith in the views of your vets, you are free to believe them. I believe in God but that's about as far as faith will take me. For things like OFA evaluations, I like science.

I haven't read the OFA site, but I'm guessing they're referring to test-retest reliability, between the prelim and final test results on a given dog.

http://en.wikipedia.org/wiki/Reliability_%28statistics%29

"According to this an OFA excellent could turn out to be OFA fair and they would still call the first evaluation "reliable.""

In which case, the above statement wouldn't be true. Test *results* aren't reliable, the testing instruments themselves are. If a dog got a fair and then an excellent, the method of evaluating would be unreliable, and neither result would stand.

Please answer the question.

With all due respect, I don't need a lesson on the scientific method. You stated that there is almost no correlation between a 6mo old and 2yr old rating. You didn't state "that because of the lack of verifiable data (in your opinion), one must assume that correlation between the two doesn't exist". Hence my original question which you have failed to answer.

Nothing to do with God.

From what I read, they posit that an OFA Excellent is "normal" and an OFA Fair is "normal" so the test is "reliable" if an Excellent later turns out to be Fair. But that's just my reading.

am not Kate but, common sense says 'almost no correlation'

at 6 months you don't even have the growth any where near finished for one. furthermore, it's the good muscling that helps form the good joint conformation by holding the femoral head in place and he's months to go until he's 2.
Condition of the dog makes a huge difference too. you have a young large boned pup , he's more than likely loose at this age. So your fair pup could easily be a higher rating at 2yrs.

this is why I think it is a waste to spend $$ on prelims at this young of an age because yeah, 'there's almost no correlation between 6mo and 2yr films)

Another thing, it is also very hard(almost impossible ) to even see FCP on films of a 6month old even if he's into the ortho's because he was gimpy on you and you were concerned(you as in general you) CT scan will show it but not reg films, not until DJD sets in will you see it. You want to know the true status of your elbows, do CT scan.

Repeat at 12 month, and that will give you a better idea.
I used to do prelims at 6 months and I got finals all over the place compare to the 6 mo prelims. I find the 12 mo to be a lot more reliable.
I doubt that they saw any arthritic changes, so it should be mostly laxity. Just swim him a lot and give him proper diet. Go and have fun with him.

I agree with the above. Just go and play with dog and repeat later. That is early and joints are loose and can sure change by 2 years. Who has not had a fair go good or better by 2 yrs. Alot have.

From www.offa.org :

A recent publication* compared the reliability of the preliminary evaluation hip grade phenotype with the 2 year old evaluation in dogs and there was 100% reliability for a preliminary grade of excellent being normal at 2 years of age (excellent, good, or fair). There was 97.9% reliability for a preliminary grade of good being normal at 2 years of age, and 76.9% reliability for a preliminary grade of fair being normal at 2 years of age. Reliability of preliminary evaluations increased as age at the time of preliminary evaluation increased, regardless of whether dogs received a preliminary evaluation of normal hip conformation or HD. For normal hip conformations, the reliability was 89.6% at 3-6 months, 93.8% at 7-12 months, and 95.2% at 13-18 months. These results suggest that preliminary evaluations of hip joint status in dogs are generally reliable. However, dogs that receive a preliminary evaluation of fair or mild hip joint conformation should be reevaluated at an older age (24 months).

Last night I was having dinner with a good friend who is a scientist full time. So I presented these results to her pretending that I they were mine. I was going to play this ruse out to get her full opinion, but I couldn't do it. When I got to the part where all the grades were collapsed to "normal" or "not normal," I just couldn't stand what she was thinking about me. A look of relief came across her face when I told her that I wasn't the one who had done this research.

I really like the person who brought up commonsense. Would you, as a person with commonsense,
think that a 6-month evaluation of Excellent that came back Fair at 2 years was a useful test--especially considering that breeding two OFA Fairs together yields about the same percentage of dysplastic puppies as breeding two OFA dysplastic?

Would you use the information from a 6-month evaluation to make a breeding decision--for example, to breed the dog before the final evaluation (as is done more often than most of us would like to believe)?

How much would a 6-month evaluation add to your confidence about the hip health of the puppy over the fact that the puppy just moved sound?

What if the 6-month puppy evaluation came back Fair? Would the test increase your confidence in keeping the puppy because about 3/4 of such puppies ended up somewhere on the "normal" spectrum? Or just make you wonder, as the OP does, what on earth to do with this information?

I like science. I may like commonsense even more.

Well my experience with OFA at an early age is dismal at best. Around twenty years ago we did three 6 month old puppies, all came back as prelim "Good". At two years of age one stayed "Good", one went to "Fair", the last went to Moderately Dysplastic. I have some friends that went through the same thing. We stopped doing Pre-lims all together except in a couple cases where we did them at 18 months. An Ortho vet that we used recommended not doing them until 18 months as he felt much could change within that time period. Just looking at the posts, other folks have different ideas but this is mine.
Now going back to the OP's question, I would run the boy on if he is really, REALLY nice. Around 15-16 months take him to a very experienced vet who does OFA's. The better ones take a shot, review it for positioning, and take another if required. A really good vet can give you an almost exact reading matching OFA.

That applies to any young evaluation - including PennHIP.

Something that no one seems to be mentioning is that the statistics the OFA doles out are skewed... I don't know of one person who submits an OFA evaluation with the vet who took the xrays is standing there telling them they won't pass... we just say oh damn and move on; maybe we try another vet for a second opinion, but OFA NEVER sees those films... so in reality, and I do believe this whole heartedly, that the number of dysplastic dogs is higher than what the OFA statistics reveal, as their data can only be based on what is actually submitted, what is not. So, that being said, have our numbers truly decreased in regards to the number of dysplastic dogs produced OR are have we just reduced the number of dogs being submitted. Don't know about the rest of you, but I am not going to give up $40 or whatever the fee is now just to have OFA tell me the same thing my ortho guy just did.

Perhaps OFA should offer a submittal with no fee for those x-rays that wouldn't pass for inclusion in the statistical database? Maybe then we could get more accurate information? Just a thought.

Well, no it doesn't apply to PennHIP in the same way as OFA because of the quality of the research supporting a correlation between early and later PennHIP evaluations and supporting PennHIP's ability to predict the development of DJD. Here's where I like science.

Do I do PennHIP at 6 months? Nah. If I am going to pay $500, I want the dog to be at least 18 months because the correlation between 18 months and 24 months is nearly 100%.

If I were worried about a particular puppy, I would probably pay for a PennHIP at 6 months. But these days I'm not really worried about hip dysplasia so I just wait until 24 months. In that 2 years, the dog may not be part of my breeding program for other reasons.

I would like to see this research. I know that OFA has done "due diligence" and selected 24 months as the age at which fewer than 5% of dogs evaluated as "normal" fail to also be normal on subsequent radiographs as they age. The few dogs I personally know about that were done multiple times by PennHIP method had very different DI scores at less than 12 months and over 24 months. Please give a reference for the correlation research. Inquiring minds want to get the facts.

Just check the research section of the pen hip website if you are an inquiring mind. No need for me to do it for you.

Whatever Kate. Go back to your hole.

I found a research abstract regarding the repeatability of DI scores within and between radiographers on the same 31 Labradors at age 2. The correlation was between 85% and 94%. This means that the DI score on x-rays of the same dog at the same age by different radiographers vary by 5-15%. Human error and interpretation

I could not find an article or abstract that specifically compared DI scores on the same dogs from x-rays taken at different ages. Such a longitudinal study is what guided OFA to select 24 months as the age for certification. Please post the reference you used for your comment suporting that findings on young x-rays are similar to those on older films of the same dog using the PennHIP method. Thanks

Some encouragement from 2 of my own case studies, two tested Good at 12 months but Excellent at 24 months.

I'd add glucosamine and chondroiton to the diet. All the best to you and yours.

After the nastiness I get on this forum, I don't see why I should help you. The study was a longitudinal study of 7 entire litters of Labrador puppies followup throughout their lifetimes with repeated PennHIP and OFA evaluations every 18 months. The study was funded by Purina and also looked at the impact of weight on development of DJD.

Look a little harder. I don't need to look.

I have to trust that your comment was without foundation if you won't support it. I saw studies on the impact of reduced feeding, comparison to OFA methods (very self-serving) and some on cats, but not a one that appeared (by title) to represent a longitudinal study of PennHIP methods/results. Without this comparison of evaluation method and scoring over the growth-span of a dog, there is no statistical basis for verifying that scoring on young dogs remains constant into adulthood. I will have to conclude that early radiographs of any type are not necessarily indicative of adult status - which was YOUR initial statement.

OFA scoring over the life-span has been evaluated in two separate studies. Both conclulded that while some dogs remain fairly constant over time, many don't. It was these studies that led to the statement of probability for adult outcome based on early score. In other words, a dog that rates excellent at 6 months is much more likely to get a "passing" score at age 2. While this seems like simple common sense, it is good to know that the facts and figures bear out the conclusion

Do as you choose. I know the study was done.

The whole question is academic to me, and I have no vested interest in it or doing your research for you or proving that I read it. I don't do 6-month evaluations, never have.

I had to laugh when you said that OFA had done due diligence to support a 24-month evaluation. Interesting, considering OFA now says that "For normal hip conformations, the reliability was 89.6% at 3-6 months, 93.8% at 7-12 months, and 95.2% at 13-18 months."
Why exactly should someone wait until 2 years?

Of course, the main issue is not the reliability of the test anyway. The main issue is how well a test predicts what a dog will produce--predictive validity.

Prove it Kate!

Did the same as you for supplementation; kept youngster in good weight and muscle; Prelim'd Good at 15M and Mild at 24M. Same radiologist. Shallow acetabula. Go figure.

This hobby is not for the faint of heart or light of wallet. Mother Nature will do what she will do.

Dog has every other passing clearance under the sun. Whatchagonnado? For any pup that makes it, it is just as much a miracle as the miracle of the pup's birth.

Kate, I recall you in the past demanding proof of claims by other breeders. Now that the shoe is on your foot it works differently. I don't think so. Take your claims and stuff them, you have no proof.

You speak out of both sides of your mouth.

As can easily happen when people throw numbers around, the percentages Kate quoted aren't related to the two studies that I mentioned. If you would like to read the longitudinal study that influenced OFA to change the certification age from 12 months to 24 months, here is the reference
Jessen CR, Spurrell FA. Radiographic detection of canine hip dysplasia in known age groups. Proceedings of the Canine Hip Dysplasia Symposium and Workshop. 1972;Oct 19-20, St. Louis, MO.

This study compared evaluations every 6 months up to 3 years of age. On dogs that were rated "normal" at 24 months, the percentage of dogs with an abnormal reading at 30 or 36 months was less than 5%. In other words, radiographic evaluation at 24 months was 95% accurate for detection of CHD.

The percentages that Kate quoted for 95.2% accuracy at 13-18 months was for radiographs graded at that age compared to radiographs of the same dog at 24 months. So, even though there is less than 5% difference on passing scores between results at 13 months and 24 months, there was still MORE than 5% difference between results at 13 months and 36 months. Numbers don't lie - but you have to understand how to make them tell the truth

What I quoted, my dear, was from the OFA website. I personally find it to be a disturbing presentation of the "truth," but it is the one published by OFA--word for word. So reading that quote, why wait until the dog is 2 years old? Remember my dear, I do my evaluations at 24 months--and I always have.

Avast you other scallywags (if there really is more than one), I'm calling you out. Shiver me timbers. If you are such a man among men, come out from under you'r rock and run a shot across the bow of the PennHIP doctor's blog. Otherwise, hold you tongue and you'r whinin’ for them that’s at your beck and call, because I ain’t.

I didn't say that you misquoted the website. I said you didn't understand what you quoted. The monograph clearly states
Corley (1997) reported on a population of over
2,000 dogs from the four breeds with the greatest number of OFA
submissions (Labrador Retrievers, Rottweilers, German Shepherds, and
Golden Retrievers). The reliability of the preliminary evaluation (3 to
18 months) was determined by comparing the initial evaluation to a
follow-up evaluation (at or after 24 months) of the same dog.

The reason you wait until age 2 is that you are most likely to get a reliable result that will be valid for the rest of the life of the dog. There is less than a 5% chance that the hips will change after 24 months. Most studies look for that "<0.05" reliability - 5% or less deviation.

At age 13-18 months, readings are only 95% of that 95% reliable. For some people, that is sufficient. Statistically, it means that about 10% of the dogs that get a clear rating at 18 months will NOT get a clear rating at 36 months. The extra 5% may not seem like much, but when I am considering the lifetime impact, I can wait the extra 6 months.


I have also done evaluations at 2+ years since OFA changed the guidelines in 1975. Prior to that, I sometimes used "final" evaluations at 13-23 months, which was the norm for THAT time. I suspect that was before YOUR time, dear.

You're right. I don't understand what I quoted. I don't understand the kind of research that OFA did or why they did it. To me it looks as if they might as well abandon categories of excellent, good, and fair, etc. in favor of "normal" and "not normal." And it looks like to me that they could make that discrimination between normal and not normal fairly well at 6 months. Good enough. Because the whole test does not have a good track record of predicting what two dogs will produce when bred. My opinion, of course.

Another thing I understand is that your interpretations of the research supporting OFA evaluations are on very shaky ground, given the quality of the research and the inherent errors possible in subjective evaluations. Heck, we hear time after time, how the three evaluators don't agree among themselves or over time, how badly some vets take the x-rays, and how many x-rays are never submitted. You are on very shaky ground, regardless of how many years you have been standing on it.