JAVMA report on Hip Dysplasia bias

[GraceAAA]

For what it's worth...there was an interesting article in this months Journal of the American Veterinary Medical Association (JAVMA) regarding the "estimates of prevalence of hip dysplasia in Rottweilers and the influence of bias on published prevalence figures".

Apparently, the conclusion is that the rate of HD in our breed is significantly higher than that which is reported by statistics (either by the OFA or other reporting agencies)...this is due, in great part, to the fact that there is no mandatory submission of hip x-rays, i.e. a breeder/owner requests x-rays that then reveal hip dyplasia as read by their GP and the x-rays are then not submitted to the OFA.

The authors of this article actually believe that the rate of HD (currently reported by the OFA at 23.3%-35.4%)...is two fold higher...at 53%-73%...which according to this article, is more consistent with the data reported on HD by other countries!

This article did not address the submission rate of x-rays for elbow dysplasia...one could speculate that reporting biases would occur in this regard as well causing the actual incidence of ED to be significantly higher than is statistically reported in the USA.

I thought it was important to bring this up in this forum because as breeders and owners, I personally think it is detrimental to the health of the Rottweiler breed when we fail to participate in the accurate and unbiased record keeping of dysplasias within our breed. Certainly, it is human nature to not want a public record/database for people to see that a dog bred by a certain person has been found to have HD but commitment to the integrity of the Rottweiler as a sound working breed must take precedence.

Here's to accurate and all inclusive record-keeping!
Andria

[Ann Felske-Jackman]

Thank you for sharing this. Unfortunately, the veterinarians help to perpetuate the bias. One of our puppy owners went for their OFA evaluation on Wednesday. Thankfully, her bitch's hips and elbows looked very good (praying that the OFA agrees ), but the friend who went with her also had her dog's hips and elbows done. Hips looked very good, but the elbows did not look like they would pass. The vet told her that most people do not send failing rads in, so to save her money. I suggested she march back there and have them include the elbows with the hips (and of course explained why). She called her breeder, who agreed also, and did submit them. However, how many times a day does this happen?

Until the OFA agrees to accept failing submissions without charge (they do for hearts and thyroid), then this is going to continue to happen. Anyone who feels strongly about the issue, please take the time to contact the OFA and urge them to change their policy on this to help encourage reporting accuracy.

Ann

[MontanaRott]

Amazing that the vet would tell the friend not to send in the possibly failing elbows, sheesh what is it, an extra 5 bucks? We had our boy done last week and his films look good and I signed for his elbow info to be released should it be a fail. Why not? The general public, who maybe puppy shopping down the road, deserve to know what this sire and dam produced. So far we are the only one's with puppies out of this litter who have had any testing done(according to the OFA data base). We have done eye's, heart, and now hips and elbows, all this on a dog who will never reproduce, but we firmly believe the information for us as well as the public is important. And I will email the OFA, for what it's worth, about their current policy.

[BostonRott]

Honestly, this is not new news (not trying to be rude). Fred Lanting published a lambasting article re: OFA submission rates years ago saying this very thing: rates of incidence are far higher than the database shows because local practitioners keep the very worst xrays back from OFA (why pay a fee to be told something obvious).

MR, I too believe that people should know, even if the dog will never be bred......the info needs to be out there on what the line is producing. It's the reason that I had both Bort and Devon OFA'd with no intentions of ever breeding either one.

[Judi W]

I agree with Gret in that this is not new and it doesn't even take a Fred to explain it. The holding back of submissions is only a tiny bit of it as is the fees. The larger part is the lack of concern/knowlege of a large number of owners. Many do not belong to any club at all so working to complete the database is not relevant to them nor do they understand any reason to even xray let alone submit. Some will have an xray taken when they find their dog can't walk without pain because they are urged to get some diagnostics done but that is the only reason. The ethical breeders want all offspring submitted so they know what they are producing and their contract provides for some form of compensation should the dog not certify which is additional incentive for the puppy buyer to xray and certify. The person who just picks out a pup from the newspaper has no incentive to invest in health clearances. For all who disparage club membership, they should keep in mind it is that group of people that encourage and in fact require health certifications or that database would be even smaller.

[GraceAAA]

Agreeded...definately not new news...but it is relatively new (and encouraging, I think) that veterinarians are speaking about it, researching it, and publicly publishing their findings.

While I know Mr. Lanting was well ahead of this article, unfortunately it seems it often takes the credibility of the veterinary communities supposed "independent" findings to create change. This article is calling upon fellow veterinarians to commit themselves to reducing the HD percentages by evidence based findings...which is a good start, albeit a bit late.

Our clinic has taken a step in that direction by requiring owners (prior to the x-ray procedure) to agree that all x-rays will be sent to the OFA regardless of results...if an owner is uncomfortable with this requirement than they are free to go elsewhere for their x-rays!

Perhaps, we will see a day where other veterinary clinics are requiring the same....one can hope!
Andria

[calebmyboy]

This may not be new news, but certainly the first time I have heard about this.

When my breeder found out Chase had HD she said she wouldn't require the xrays for OFA, she would still give me a replacement puppy. I thought she was being kind and trying to save me money.

Now I am thinking she just didn't want this information in the data base

And I should go ahead and have the xrays done & sent in. So thank you for reposting this information.

[Patty1231]

Although I new the rate was high, I am surprised that it is that high. That gives a person at best a 50/50 chance of a having a clear dog; and likely a lower chance than that. Very discouraging. Although HD is certainly not a death sentence and dogs diagnosed can live normal to fairly normal lives, there are so many that do require surgery. Are there any reports that show the percentage of diagnosed HD cases requiring surgery versus those that don't?

[BostonRott]

Originally Posted by GraceAAA

The authors of this article actually believe that the rate of HD (currently reported by the OFA at 23.3%-35.4%)...is two fold higher...at 53%-73%...which according to this article, is more consistent with the data reported on HD by other countries!

I agree with Patty that this seems absurdly high. Do you actually have the article? What other countries, and specifically what other registries are they referring to for these "assumed" rates.

I am an ADRK member and have their Dogbase program. I have never counted the % dysplastic of tested dogs, but somehow I strongly doubt that it's 1/2. I'm curious to know how the authors arrived at these conclusions.

I also don't believe the increased percentages based on my own personal experience. I've now owned 6 pedigreed Rottweilers. Some are related, some are not:

Bort / Devon -- full brother sister by repeat breeding. Bort is OFA Ex, Devon is OFA Good.

Froli / Banja / Vikka -- Froli carries no common dogs with Bort/Devon within 6 generations and is OFA Good. Banja is Froli's daughter and is fully expected to pass her OFA next month. Banja and Vikka are cousins (Banja's sire and Vikka's dam are littermates). Vikka is OFA Excellent.

Xcel -- Xcel's granddam is Vikka's great-granddam, and he will be prelimmed next month at 6mos.

So for the supposed 53% rate, I should have had 3 dysplastic dogs (Xcel is the only one we truly know nothing about yet). For the 73% rate, I should have 4+ dysplastic dogs. I do not baby my dogs, I do not inhibit their exercise.......no kid glove treatments to create false passing OFA grades.

Am I really THAT lucky in picking puppies that I manage to stay in the minority unaffected percentage? Or are the authors extrapolating a tad much? Anyone else have thoughts on this??

[Judi W]

Slow down now. How high it is out of the total population is totally speculative because the answer is - we don't know.

As far as chances go, again the 50/50 at best is not correct. If you are selecting a dog from rescue, it is probably less than 50/50 because most of those dogs will have come from uncaring and unknowlegeable breeding. If you are acquiring a dog where careful selection has been made over the generations for soundness, your chances of having a sound dog can be as high 90% or even better. If I am looking at 3 or so generations where the litters (all sibs at all levels) are 90% or better OFA certified, I'm am pretty darn certain that I am going to have sound offspring.

If you are simply acquiring your dog from a grab bag, then maybe the idea of 50/50 is close but that does not apply to the sub groups of the population or to an individual dog that one acquires.

[GraceAAA]

Yup, I do have the article...one of the perks of working at a vet clinic! ;0) I'd be glad to mail it to you if you want to e-mail me your address.

Other countries referenced were Switzerland, Poland, Norway, Israel, Canada and Sweden...with a reference range dating back to 1972 statistics. The reporting registry is not listed.

As we all know, there are so many variables in regards to the development of hip dyplasia (genetics, trauma, diet, rapid growth, excessive exercise...to name but a few variables) so, I think the percentages we experience with our own dogs can certainly be in contrast to what they are reporting as percentages within the general population of pet and pedigreed dogs.

And, so many variables certainly exist within the reporting of OFA results. The authors range of HD statistics is due to such variables as the OFA intrepretation of the x-rays and differing views from radiologist to radiologist. Whether, or, not the CCO (caudal curvilinear osteophyte) was counted as an additional sign of osteoarthritis accounted also for the range of the statistics. When the CCO is not counted...than obviously the statistical count is lower.

The authors also express the question of whether, or, not the preliminary hip evaluation process serves to acceptably predict later OFA scores at 2 years of age and of DJD by one year of age. Apparently, there is a "reported" high incidence of false-negative reports on hip pre-lims. For those of you who have done pre-liminary x-rays, have the x-rays at 2+ years of age been consistent with those taken as preliminaries at 6-12 months?

As the article states in it's final paragraph, "True disease prevalence is difficult to predict...because it is not possible to survey each member of the entire population...it is neccessary to estimate prevalence by studying a representative sample of the population....the sources of error in disease prevalence estimation are many..."

Andria

^Silver^: Assistance, Seeing-eye, Seizure Alert and Therapy Dog
((Baby Joy)) Kriznik's Image of Faith CGC
and their little pack!

[Judi W]

Just a quick note regarding prelims. The reason that OFA selected 2 years of age for certification is because there are still changes taking place prior to that and at two it if felt that the diagnosis is quite reliable although still not 100%. (they have the percentages posted, I just do not recall them at the moment). A prelim that is positive for HD is not very darn likely to improve with age. A clear prelim can still deteriorate with the likelihood dependent upon the age of the prelim.

[GraceAAA]

That is pretty much what we have seen at the clinic...only a few positive HD prelims have made it to fair by 2 years with dietary supplementation (and maybe some good luck?!?) More good/fair ratings declining by two years.

[fbkeays]

Maybe I missed this, but is the dx of HD based solely on OFA, or did they survey "regular" vets on their dx of HD?
If they believed regular vets, then no wonder the % of HD is so high. I had my two males x-rayed (one at 12 months and the other at 18 months) by two different vets, both put under. Both were dx as having HD. Guess what, dog that was x-rayed at 12 months was badly positioned. GDC prelimed him excellent at 18 months and OFA'd good at 24 months. The other dog was positioned well enough, but the vet was pointing out "problems" that were normal expressions that are seen on all hip x-rays. I took the x-ray and compared the "problems" with both of my older dogs that had OFA good and there were no differences. The dog was OFA'd fair at 24 months. I may re-x-ray him in the future as his positioning could have been better.
I will never believe a "regular" vet when it comes to HD.