Gassy cob suggestion sorry ted....have you asked for a microbiome assessment of her gut microbes....there might be something there which is not helping the problem, which is over producing with the change to grass?
It is his 10th birthday tomorrow. Someone needs to wish him happy birthday, he has no mates anymore and his sister still hates him so no chance of a card or carrot off her. He is on a permanent diet, his haynet is big enough for a gerbil and his two bowls of straw chop with 2 fibre nuggets really don't fill the gap. If anyone could smuggle a bag of extra sticky goodies in he would be your friend forever. No parties for 18 months and nothing on the agenda either. Life is boring, hours of walking, hours of waiting for the grass to grow in his ryvita paddock. But, the vet is pleased with his weight loss - bonus !
Happy birthday my gorgeous, bonkers, feral carthorse. You will never know how lucky you were when you landed in a heap with me all those years ago.