Dehydrated Fawn??? Help...

I had 2 twin buck fawns and I noticed they both had bloody stools 2 weeks ago. Gave Ivomectin and both cleared up and looked great. This week I noticed we could walk extremely close without them jumping up. We gave Target Electromax, B-12, and pedialyte hoping that they were only dehydrated. We found one buck dead and we are expecting the other one to take the same path unless we do something quick. His belly is full like he is eating but today he is too lazy to get up. If he cant stand i dont think he is eating. It has been 100-105 heat index this past week in IL. Today was only in the 80s so it has cooled off so the heat shouldnt be a factor anymore. I forced 15oz into him and stimulated him to see perfect dark green pellets. We noticed there was a beaten trail to where he was laying and it was from him rolling over and over and over because he could not stand up to walk. We pick him up to put him on his feet and he is extremely shaky but can walk about 5 yards. His legs kept cramping up and sticking straight out when we were feeding him. That tells me lack of fluids and muscle cramps from dehydration. Again tonight we just gave another cc of B-12, Electromax, Milk, water, and pedialyte, and thinking about pullling from the mother but we can walk right up to him so dont know if thats neccessary yet. We have not seen him pee yet so just wondering if there could be something with his internals making him look like he has a full belly but its really not, or why is his stool perfect if hes not getting any milk from mom. Little Boomer top and bottom, twin bucks and just lost one. Please help me save this little guy. Thanks alot.

Thanks Drew, I have been giving Target fawn paste and I think that is whats keeping him going. We just fed him another 10 oz milk and he sucked the bottle down this time. No forceing about it. Im now wondering if dehyration is even the problem. He is full as a tick and looks like he is about to pop. He is too weak to push out his stool I think. I stimulated him and he just pushed out 3 handfuls of pellets but he still has not urinated. It looks more like he has plenty of fluids in him but cant get them processed through. Any more suggestions??

Another thing, Is there a way to stimulate the penis or what can you do to make them urinate? Theres no problem making him stool but not seeing him pee is worrying me. As for the Plasmalyte Electrolytes, Do I need to go to the vet for that or would rural king or a farming implement store have that?