Shaking goat,goat weight,and strange behaviour

I have 5 Nigerian dwarf goats,all a little less than a year,I'd have to look at the papers to know for sure,2 are males,one being a weather and the other is still a tiny baby we recused,all the others are does we plan to breed with a stud service as we dont feel like keeping a stud around and separate befor breeding,but the weather is acting strange now,2 days ago he was sitting down in the stall when I got to them,every morning a little after 7 I move all the big goats out to the pasture to graze on what ever they can find,but when I went to move them he wouldn't get up,usually he is standing on the door to the stall with one or two of the others and he is pretty much my friendliest goat other than the bottle baby,and even when I called him he would get up even when I shook the food pale,once I kinda lifted him up he moved around a little but acted depressed and kinda lethargic,he has been eating but not with the gusto that all the other goats and he always do,and he is shaking at his rear end,I have seen him both poop and pee scince then but only once,he may be going while I'm not out there but I dont know for sure,I have them on i believe purina starter/grower medicated goat feed,they get probably 2 cups of food or so between the 4 of them every day,enough in the stall feeder to keep them in there while come to close the door and a little bit more in the morning on a table in the pasture,the stall always has hay,and leaves and it gets flipped every day and I add new hay about once a week or when I remember,not really on a exact schedule,and they have hay available in the stall all the time,but I dont think they eat it after they stomp on it at night, so I'm going to rig up a way for them to have a whole bale of hay in there without stomping it,sorry for the segways off topic,I'm trying to be very specific,I dont know what is wrong with him but as anyone with animals would say,trying to get past a unnecessary vet visit is always the preferred option,I have dewormed all of them,I don't remember the brand,but the dosage is 2.6 ml per 100 pounds, or .6 ml per 25 pounds,and every day he seemed to be getting better but today's he seems to have a platue and Is not getting better anymore and I don't what is wrong with him or what to do,they had limited access to hay for a little while,so maybe he has something called acidosis, hopefully I spent that right,I was also wondering if his stomach is sopost to be kinda firm,almost bloated,maybe it's part of his problem and they need more hay or something,one other questions is if they are over weight,I'll have to weigh them again but I believe that the heaviest was 40 pounds,I'll try to add a few pictures of them if it allows me,I was also wondering when moving the baby goat in with the big ones is safe,he is I believe less than 8 weeks old,and he isnt fixed,yet,and two of the big goats are mean to him,but every day when I feed them on the table I bring him with me to try and get then use to him being around them and eating with them,I'm worried about him actually getting lucky with one of the girls or getting hurt by one of the girls,my weather,the one who isn't feeling good is perfectly fine around him,any help would be greatly appreciated,I'm also thinking about switching thier mineral block to the kalmcum kind,forgive me if I spelt that wrong,I keep hearing that they need a mineral block but I can't find out witch I should use,any help would be great ,the weather is the one on the end,all brown