Spinoff/ Horse Care: Draft/TB/QH/Arab/Appy breeders, do you test for EPSM/PSSM/RER?

[M. O'Connor]

It seems that there are some pretty strong (and quickly expressed) opinions expressed on THIS (http://www.chronicleforums.com/Forum/showthread.php?t=210436) thread: "Feeding the EPSM broodmare"...which leads me to wonder:

As it becomes more evident that the root causes of these related metabolic syndromes are genetic in origin, how routine is it to test prospective beeding animals in the breeds affected by them? Are the risks of winding up with a severely debilitated animal (considering that the majority of cases respond very well to dietary modification) that high?

I have an RER TB gelding, but it never occurred to me to have a muscle biopsy done on my (unrelated) TB mare, who has produced a very nice foal for us, and with luck will do so again in the future. Does a horse that responds positively to a high fat diet (as many do) simply have no place in a breeding program? Or is the combination of genetic factors that would produce an offspring that can't lead a useful life so high that the risk is not worth taking?

Notwithstanding that the OP's on that thread's mare in question has not been diagnosed by a vet with this disorder, but apparently might do well following the feeding modifications recommended for conditions that respond to a low starch/high fat diet, it seems as if several who responded feel there is ample reason to discourage this perfect stranger from breeding what has been a very useful horse to her, what are the opinions of breeders here?

[pintopiaffe]

Well, obviously I chimed in over there ;)

I would test ANY breeding animal that had suspect symptoms, or relatives with suspect symptoms.

As I said, I have the daughter of a mare who was never diagnosed by the vet (My vet is a Repro specialist and had not heard of EPSM when I first brought it up to him, and we didn't know yet the dominant nature of the genes back then) and had very mild symptoms--difficulty with the farrier despite exemplary manners and temperament, lost her really extravagant movement that she had as a young horse... She went on "The Diet" by default as I was feeding a severely COPD horse who she was turned out with. And I realized her movement *came back*. She was perfect for the farrier. So I did more research etc. She had two 'relapses' right on schedule, which to me pretty much proved the 'diagnosis.'

She died before I could test her. I now have her daughter and son. Neither have ever taken a bad step, but the daughter will be tested before ever being bred. Son is a gelding. Both have been on low starch/high fiber/higher fat than the average diet all their lives, and on 24/7 turnout. Hard to say if they'd be symptom free with different management.

If it truly is EPSM, it came through the APHA sire line. I still have the mare's dam, who has had 8 foals, the only one of which was suspect was by the APHA sire. He died as a 3yo of twisted gut. Mare died of twisted gut. Most likely mare's was pregnancy related--5 weeks post foaling, *just* outside the window to call it for sure, but... still, makes you wonder a little bit.

At any rate, Arabs I breed are testd for SCIDS if there is any doubt. (My stallion's sire & dam are both tested clear, so no need to test him) Why would I breed the filly if I had any doubt whatsoever? A relatively cheap hair test and we'll know.

I can't see that I'd be using any Draft stallions at any point, but I would absolutely test--and offer to pay for it--if I was. Other breeds with less propensity, I would test based on suspect symptoms. There are enough unwanted/unplaceable horses that are perfectly sound and fine. I breed exceptional individuals for superior attributes. I won't breed an 'average' animal... why would I breed one with a suspect genetic disease?

And actually, thanks to that other thread I pulled the hair, and just have to print out the submission form when I go to my other job (no printer at home) to get it sent in. ;)

[M. O'Connor]

Did you ever get around to posting a link to where the submission form is available? To whom do you submit it. Who performs the test?

[Wayside]

I don't breed drafts myself, but I worked closely with a few well-respected and successful people who do when I was actively showing my Belgian gelding. Both of the people I can recall talking to about the topic regularly tested breeding stock for junctional epidermolysis bullosa (JEB), in order to avoid passing on that disorder.

However, both of them routinely fed all their horses a diet consistant with Dr. Valentine's EPSM guidelines. And my understanding was that in many circles, that's simply how people feel draft horses should be fed. Dr. Valentine at one point speculated that over half of all draft horses were genetically predisposed to developing EPSM. I've always fed my draft gelding as if he could develop it, althought I've never had any indication that he is affected.

The school of thought with the few draft breeders I've worked with with seemed to be that they would test and cull any horse that developed symptoms despite being fed "properly", but that the vast majority of horses would never have any problem as long as they were fed a "normal" diet. Normal or proper being, in this case, a diet similiar to that recommended for EPSM. In their eyes, culling a horse that is perfectly fine and capable on a "normal" routine, but might get sick if it were fed differently would be like culling a horse that might get sick if you fed it a diet of cheetos and pork rinds, or might get injured if you put it in an unsafe situation. Sort of a "As long as you're not doing things you shouldn't do with your horse, it won't be a problem."

And for reference, there are a lot of good articles on the topic at http://www.ruralheritage.com/vet_clinic/index.htm#virtual

[Wayside]

Did you ever get around to posting a link to where the submission form is available? To whom do you submit it. Who performs the test?

The last paragraph at the bottom of the article "Taking a Muscle Biopsy for EPSM" at http://www.ruralheritage.com/vet_clinic/epsm_biopsy.htm states:


Beth A. Valentine, DVM, PhD, is a veterinary pathologist at the Oregon State University College of Veterinary Medicine in Corvallis, this site's virtual vet, and co-author of Draft Horses, an Owner's Manual. She will be happy to email, fax, or mail you or your veterinarian a set of instructions on how to take a muscle biopsy and how to package and send it to the OSU laboratory. If you would like to receive these instructions, please contact Beth.Valentine@oregonstate.edu.

[M. O'Connor]

CHEETOS and PORK RINDS!!!:lol:

Thanks Wayside, it was Pintopiaffe I had asked about the link...She seems to feel that a 'hair test' will yield the same results as a muscle biopsy, and that it's indicated before breeding--that's the link I was inquiring about.

Dr. Valentine and Dr. Stephanie Valberg are the researchers that come to mind instantly on this topic, and both have written about the muscle biopsy procedure. I've never seen that either one recommends testing of all breeding stock. Doing so seems extreme, which is why I began this thread.

[Sithly]

Well, the common sense approach would be to test any breeding stock that is symptomatic. But this being CotH, someone always has to take it to extremes.

[pintopiaffe]

from the other thread:

For those looking for the testing:
http://www.cvm.umn.edu/umec/lab/Advances_in_PSSM.html is the link with an excellent, if somewhat simplistic flow chart...

http://www.vdl.umn.edu/prod/groups/c.../cvm_88878.pdf (http://www.vdl.umn.edu/prod/groups/cvm/@pub/@cvm/@vdl/documents/asset/cvm_88878.pdf) is the form for submission.


I guess I just don't see it as extreme to test a symptmatic horse before breeding it. :no:

[Wayside]

CHEETOS and PORK RINDS!!!:lol:

Thanks Wayside, it was Pintopiaffe I had asked about the link...She seems to feel that a 'hair test' will yield the same results as a muscle biopsy, and that it's indicated before breeding--that's the link I was inquiring about.

Dr. Valentine and Dr. Stephanie Valberg are the researchers that come to mind instantly on this topic, and both have written about the muscle biopsy procedure. I've never seen that either one recommends testing of all breeding stock. Doing so seems extreme, which is why I began this thread.

Glad you got a good chuckle out of that one, M. O'Connor :lol:

Obviously that was a very silly example, but I think you can kind of get a feel for the general idea without taking it to that extreme.

Not sure if this was what Pintopiaffe was referring to, but it looks like the University of Minnesota might be able to do the hair and blood testing. http://www.cvm.umn.edu/umec/lab/Advances_in_PSSM.html

[Wayside]

Thanks Pintopiaffe. That's what I get for stopping to pet the dog before hitting "submit". :)