Help!! Im new at all this. Have a fawn with possible dehydration and/or bloat!!!

So I've recently taken on a fawn. I couldn't tell you the age. Still has spots. I have never done this before so I honestly do not know very much about them. It has been on manna pro milk replacer for about 4-5 weeks and has had some diarrhea here and there. Well now I do not believe she is pooping or not. She wanders my property throughout the day and comes into my barn at night. As the woods aren't safe at night as we all know. Well she had her morning bottle with no issues. We walked in our normal walk to the wooded area of my property and I noticed her eyes were not looking as they have looked. Kinda budge out a bit and the skin around her eyes seems to look like as if it opening up more. And her ears looked at though they are slightly folding at the tips. Which I do know is a sign of dehydration. If she is dehydration then how to I get her rehydrate. If it's bloat how do I help with that? Please help!!!!