Just so it's said, I plan on talking with my vet. In the meantime, what would you feed a skinny (not super skinny but you can see his ribs through his winter coat) IR, Cushings pony that had a severe laminitic episode which is how the IR and Cushings was discovered?
Contact Dr. Elenor Kellon ASAP. Just google her, you will find her web groups, and a contact Email. There is an emergency diet on her IR website. You can enlist her help as a vet for your pony...most local vets are not specialists in IR and Cishings. She is. Just make sure you are soaking hay and draining it until you can locate tested, low sigar hay.
I have a laminitic horse who is 8 now - foundered at 3. Thankfully he had minimal rotation and is sound, but he is very reactive. He gets every illness in the neighborhood which is a pain. He reacts to vaccines so we stopped everything but tetanus.....its been a long road.
My guy is 17'2 and keeping weight on him is really tough. He gets skinny in the winter. One of my new neighbors (who didnt know me or my horses history) threatened to call the humane society because she thought I was starving him......pissed me off but thats another story.
What HAS worked for me are Pellets. He gets all the hay he will eat. But he is a grazer and eats hay, walks around, eats some more, walks around. Doesnt matter which hay I feed him = I have several grass and timothy blends and he eats but likes to stop and watch the birds fly by.......sigh.
I now feed him about 6 pounds of timothy pellets soaked in water every night. I also feet him about 3 pounds of Purina ultium with the timothy pellets as it is low sugar. Its worked. Id like more weight on his topline but finally his ribs no longer show and hiships don't stick out as much. This horse will be a continuous project. I work with an holistic vet who has really helped. I have him on some herbs that are helping him. I can share the info about the hoilistic vet and herbs etc if you want to PM me.