Dr. Beth,

We have a team of 8 year old Bel/perc geldings, half brothers that we have had for 3 years. We use them regularly for logging, sugaring, manure spreading, and making hay as well as some riding. They are in good condition and well muscled. We became concerned this spring with one horse, "Don" spreading manure because he was really having trouble keeping up with his teammate. Respiration rate would become very high and we had to rest a lot because of him. We generally limited ourselves to 10 loads a day because it just seemed like too much for him. I'm thankful that we own your book on draft horses because it led me to investigate EPSM as a possibility even though we weren't experiencing classic symptoms. The only other hint we had was that he was dragging one hind toe enough to cause some wear.

We had the vet come and give a thorough exam, and her comment was that "he didn't look like an EPSM horse"..he really is a muscly horse and generally moves nicely. she could find nothing unusual in his exam except that his resting heart and resp rate seemed a little high...42 and 19. We send bloodwork into Univ. Minn. to have a genetic evaluation and he came back P/P.

After reading through the paperwork that came back with the results I am a little overwhelmed, especially with the indication that the P/P is rare, severe, and tougher to manage. Fortunately our management has been somewhat in line with recommendatios... they are on good quality pasture 16 hours a day with regular exercise, no grain. They had not been getting selenium at all until about a month ago, and are now getting 3 mg a day. They have been getting 3 cups of oil a day each in a little beet pulp for two weeks now. ( I feed this out in only one feeding, do you think that is ok?)

My main questions are about the exercise program. There are very strict and gradual guidelines outlined in the paper from UMN, starting with 3 min a day on the lungeline. I am feeling that we have caught this at an early stage and am wondering if you could recommend a more modified regime to build his muscles up to use oil? We are due to start cutting second cut hay very soon and I am wondering how to approach this. Don's wellbeing and recovery comes first, but we would definitely like to be mowing with him (we don't really have any other options). Don actually does quite well with the mowing, it was the long days of tedding and raking that seemed to really get to him, and we do have a haflinger who could help out with the tedding and raking if need be.

So, my specific question is, how much exertion is too much during this transition period?

second question is...once we have been on the diet for months and we are hopefully in recovery mode, how easily will he adapt to having a 20 minute ride one day and a 5 hour work day the next? is this type of variability in his muscle usage possible?

Thanks so much for this great resource, I have learned so much from reviewing the posts here.

Kristan

I am so glad that you were able to confirm EPSM as the cause of the problems in your horse. It can be very hard to "see" an EPSM draft. Given that breeding I would predict that at least half of your team is also "metabolically different" and prone to EPSM. I have been constantly amazed at how stoic drafts with EPSM can be. So it is really good that you have caught this now. 3 cups of oil is a good 1500 pound horse "dose" - be sure to adjust according to horse weight, and make all changes gradually.

As to exercise, I have never tried to provide a strict exercise guideline because every horse is different. As much exercise and turnout time as possible are important, but I suggest you let your horse be your guide as to how much is too much. The type of work you are doing is ideal for muscle fitness. Remember that it takes about 4 months for full fat adaptation so don't panic if you still have issues during this time. And, if he is doing well after 4 months or so, and if you can provide plenty of turnout time in between working, that 20 minutes 1 day and 5 hours the next should not be an issue. Being double positive (P/P), though, be aware that he may be more difficult to control than a P/N (single positive) horse. Most of the information on ease of control and genetic makeup is related to light horses, though - I'm honestly not sure how well they apply to drafts. You won't know until you try! Here's hoping for good news in 4 months or so, and please let us know.