The leg lifting/stretching can be a sign associated with muscle disease – for example EPSM.  Selenium deficiency can cause signs very similar to EPSM as I’m discovering with my gang, and I’ve often thought that a lot of people might think a horse was sluggish due to arthritis, when it can be muscle pain from selenium deficiency.

 

If it was me, I’d have a comprehensive blood test to include muscle enzymes (especially CK) and liver enzymes as well as cell counts... just to see if that points you in any particular direction.  Just ask the vet for that.  Make sure the blood’s taken at least a couple of days after work of any kind, and at home with no stress/exertion from travelling or anything else.  This will make sure you get a true baseline blood sample.  Ask for a copy of the full blood report and see for yourself if muscle enzymes are raised even a little above reference range.  My guys have ranged between being only about 100 units over reference up to about 3,600 units above reference, and all have shown varying degrees of work intolerance, and one does the leg stretching thing.  If that shows anything muscular, worth having your forage tested for selenium, and checking that the total dietary intake per day (including grass, hay etc and all hard feeds) comes to at least 1mg selenium per 500kg horse per day.  If you are providing selenium in a feed of any kind, make sure it’s organic selenium (selenium yeast) as it’s more bioavailable than sodium selenite.

 

Might be nothing to do with that, but EPSM and shivers have definitely been linked in some cases.

 

Sarah