Have been recommened to feed Epsom Salts for my driving ponies which are working quite hard, but I can't find anywhere how much to feed, you would have thought that the product would have the information on it!!
Thats good and old fashioned! (As am I!) A small scoop - about 2 teaspoons - per day should be OK. Or you could provide a seperate salt lick. I'm not a huge fan of feeding salts rather than letting the horse choose and it is quite difficult to know exactly how much they need. But start at 2 teaspoons and work up from there. If they start drinking and peeing like crazy - or if they get really loose poo - you've gone a bit too far.