This is an archived Horseadvice.com Discussion. The parent article and menus are available on the navigation menu below:
HorseAdvice.com » Diseases of Horses » Lameness » Joint, Bone, Ligament Diseases » OCD and DOD in Horses »
  Discussion on Research Summary: Strong Support for OCD Pathogenesis
Author Message
Moderator:
DrO

Posted on Monday, Nov 17, 2008 - 8:26 am:

More support for the idea that OCD is commonly caused by a defect in perfusion of the growth plate do to interrupted blood supply at the level of the ossification front at the end of the growing diaphysis of the bone. Also of interest is the high incidence of lesions found in clinically normal foals of parents with known OCD of the hock. We need to quit breeding horses with OCD lesions guys. Still unknown is how nutrition and exercise may play a role in converting subclinical lesions to lameness. It stills seem very reasonable to me that keeping foals on the slightly thin side to moderate growth rate while maintaining a well balanced diet is your best bet. There are still some questions of what is an optimum diet however.
DrO

Bone. 2008 Sep;43(3):574-83. Epub 2008 May 15.
Micro-computed tomography of early lesions of osteochonDrOsis in the tarsus of foals.

Olstad K, Cnudde V, Masschaele B, Thomsen R, Dolvik NI.

Norwegian School of Veterinary Science, Department of Companion Animal Clinical Sciences, Section for Equine Medicine and Surgery, Post box 8146 Dep., N-0033 Oslo, Norway. kristin.olstad@veths.no

INTRODUCTION: OsteochonDrOsis (OC) is an important developmental orthopedic disease of human and equine patients. The disease is defined as a focal disturbance in enchondral ossification. In horses, the disturbance can occur secondary to failure of the blood supply to growth cartilage. Diagnosis of the early, subclinical stages that can clarify the etiology is currently confined to cross-sectional histological examination. The potential for micro-computed tomography (micro-CT) with angiography to detect early lesions of OC has not yet been investigated. MATERIALS AND METHODS: Nine Standardbred foals bred from parents with OC of the tarsocrural joint were sacrificed at weekly intervals from birth to 7 weeks of age. Permanent barium angiograms were created within one hind limb post mortem, and samples collected from two predilection sites for OC within the tarsocrural joint of the perfused hind limb. The resulting 18 sample blocks were scanned with a custom-built micro-CT equipment set-up, and analyzed as 2D slices and 3D volume rendered models before sectioning for conventional histological examination. RESULTS: Histological examination identified eight early lesions in seven locations within six joints from the nine foals. Micro-CT with angiography was able to detect seven lesions in the same sites as histological examination. Lesions consisted of non-perfused foci within growth cartilage. No perfused vessels exited from subchondral bone deep to any lesion. Six of the seven lesions were associated with focal defects in the subchondral bone plate. Evidence of ongoing ossification was seen in three out of the seven lesions and included one separate center of ossification. CONCLUSION: Micro-CT was a useful technique for examination of early lesions of OC. The results of micro-CT were compatible with failure of cartilage canal vessels at the point where they cross the ossification front. Resultant areas of ischemic chonDrOnecrosis were associated with focal delay in enchondral ossification as visualized in 3D volume rendered models. Micro-CT combined with histology clarified the role of different forms of ossification in the secondary repair responses to lesions.
Member:
ekaufman

Posted on Monday, Nov 17, 2008 - 10:10 am:

Well, agreed, but I'd love to see the AVMA take a stronger stand on this issue. Specifically, I think it should be protocol that any stallion or mare with a finding of OCD have "not a candidate for breeding" added to the prognosis section of the veterinary report. If the clinical studies support this statement (and it seems that they do, or soon will), then the findings and their meaning need to go into the horse's medical record in a very clear way.

In the last year, I've seen several nice sporthorse mares who have had OCD surgery advertised for riding and breeding, with the apparent acquiescence of the veterinary team. Two of these horses were at facilities that have sent horses to the Olympics, and the buyer's presumption would be that these folks knew what they were talking about. It's a bad scene.
Member:
maggienm

Posted on Tuesday, Nov 18, 2008 - 6:58 pm:

You bet Elizabeth, if breeders would stop breeding these lovely animals that they know won't stay sound then young girls like my neighbor won't have their heart broken when they finally get their dream horse only to find they got a 'deal' for a reason.
Member:
rtrotter

Posted on Wednesday, Nov 19, 2008 - 8:28 am:

Perhaps I have a different perspective on this topic coming from the racehorse side of this and seeing how many breeding farms deal with the OCD problem. And while I agree that not breeding OCD positive horses might be one solution to this problem, I do not think this is very likely. I would rather see the part that nutrition plays in the problem and just exactly what should be done if you do not want OCD's in the first place.

If anyone has ever been to a standardbred or thoroughbred yearling auction, the first thing that you notice is that the horses look like aged horses rather than yearlings, they look like they can step foot onto the racetrack without one days worth of training. They are fed too much, kept in a stall, sometimes with very little turnout and are sales prepped by either ponying or using an equicizor. They look the part way before they are ready and they go for a lot of money when they hit the sales ring, their breeding and conformation get the big money. And this is the root of the problem, the money.

Most breeding farms use feeds that are cost effective, but do not take into consideration the different needs of different stages of development in the young and growing foals and up until weaning they are eating the same feed as their dams???

This tends to go on year after year, therefore is it any wonder why OCD's are found in many racehorses.

I think disclosure is the way to go, but that would mean breeders would have to be ethical and honest and not out to make a big buck. It also means that buyers should request a set of pre-purchase xrays before committing their dollars to buying any horse, especially one that is gotten for a 'deal'. Educating new owners or owners that are looking for a horse that haven't owned one before, usually fall in love with the horse they eventually wind up with and it is usually very hard to talk them out of it once that fall in love stuff starts.

It happened to me with my first horse many years ago. I did not have her completely vetted, I fell in love with her (I was young, dumb, and stupid). I couldn't figure out why she acted so strangely under saddle, a few months later I found out she had a congenital hip malformation and was basically unrideable ( this was 40 years ago, way before I had any knowledge of equine chiropractors). Had the vet looked at her before I bought her, maybe he could have changed my mind.

Anyway, sorry for the long post but the issue of OCD's is going to take a lot longer and more studies to ever be solved.

Rachelle
Moderator:
DrO

Posted on Thursday, Nov 20, 2008 - 8:36 am:

Hello Rachelle,
The problem is the more we learn about OCD the less nutrition seems to do with the clinical problem. Experimentally toxic and deficient amounts of some substances can induce or worsen joint pathology but in well cared for horses this would be the exception and not the rule. Currently there is no known special diet that prevents or even decreases the incidence of OC in horses it will be great if such a fix is found but until then we best deal with the facts as we know them. Whether folks will be willing to make decisions based on the facts is always a question however.
DrO
Member:
rtrotter

Posted on Thursday, Nov 20, 2008 - 10:13 am:

Hi Dr. O,

I have just sent an email to the vet ( Dr. Beebe) that put together the formula for the OCD Pellets that I have been using for a number of years with great success.

One of the reasons I started with these pellets was for the possibility of preventing the OCD's in the first place.

One of the recommendations ( and also one of the guarantees) was that if these pellets were fed to pregnant mares during their last trimester that the resulting foals would have a significantly less incidence of OCD's when xrayed as yearlings as compared to previous years xrays from the same farm with the same feeding program without the OCD Pellets. I am assuming ( I know, bad word) that they had already conducted several studies like this in order to provide the needed background to be able to offer the significant refund that was part of the guarantee. I need the research study(or studies)reference to 'support my point.' Hopefully, they will be able to provide this.

If you are interested, they have several articles and resources on their site www.ocdpellets.com that are available for your viewing.

I'll keep you posted and or post the links to the studies if I get them.
Moderator:
DrO

Posted on Thursday, Nov 20, 2008 - 8:14 pm:

A very clever guarantee indeed Rachelle and one that may have nothing to do with the efficacy of the product: many products that are without value offer such guarantees. A close look at the guarantee itself yields a hypothesis where there may indeed be a lower incidence of OCD the year following it's use though the product is not effective. Consider the reason someone might go looking for such a product in the first place: a high incidence of OC in a particular year. If you had a particularly bad year averages suggest it is likely the next year will be better.

Going to the site the first thing noted is that the pathogenesis of what causes OCD that it puts forth is incorrect at least by what we know right now. I really don't see any science quoted on the site that supports their statements, indeed I see them quoting experts like Dr McIlwraith on issues unrelated to the products efficacy, but DrW was lamenting just this week in some magazine that such products as this are sold with little or no evidence to back them up. Currently there is no science out there that shows supplements or nutraceuticals that will reduce the incidence of OC in otherwise well fed foals or even not so well fed foals for that matter. Intentional attempts to create deficiencies or toxicities with some minerals have increased the incidence of OCD but the relation between this and what is seen clinically is uncertain.
DrO
Home Page | Top of Page | Join Us!
Horseadvice.com is a BBB Accredited Business. Click for the BBB Business Review of this Horse Training in Stokesdale NC