Hello
Given the information you have just provided, if the foal were mine I would give him 3 CC Kayro Syrup one of more times a day. It sounds like his blood sugar is/has dropped and sounds like an incident I had some years agao with my foals. I would also wean the mare off of sweet feed and give her something without all the molasses,
It is less likely in my opinion that the foal is having seizures, than his blood sugar being low. Low blood sugar is very common in miniature horses and has not been mentioned much on this forum in some time but is a topic that was discussed in length many years ago. It was the advise of this forum that helped me with my problem then, and I use it still - it works! Some times a mare after foaling will drop blood sugar levels, wobble, stagger, drop her head etc. Kayro brings them right back, it also helps to increase their appetite if you have one that does not particularily want to eat.
Good luck,