Hi Mtegge!!
Sorry to hear about your sap problems, but I feel your pain! We don't have that many real pine trees at our house, but we do have those pesky cedars and they are just as bad, if not worse! And they're not near as pretty! The only thing I've found that Really gets this stuff off is WD40. Yep, the wonder spray. It's good for so many things. True, it doesn't smell near as good as Show Sheen, but works just the same. So of course you should bathe them afterwards, or if it's just a small spot you can scrub it with a dry towel and get it pretty good, but it takes something oily-based and slick like Show Sheen, only WD40 is a lot cheaper and I always have it around!
Let us know!
oh p.s. I would recommend testing it on a small spot first, in case your mare has sensitive skin, but it's never bothered any horse I've ever used it on.
. . .and ride that pony fast
like a cowboy from the past
be young and wild and free
like Texas in 1880. . .