disoriented

We have a 3 yrs old buck that when I went to check him today....seems disoriented. To look at him he looks alert, but when he walks he is wobbly. Then he started going around in circles like a dog chasing his tail. Does not look like he is loosing weight. ANY suggestions what to do or look...

I have a doe that came from auction. Yesterday I noticed her ears were both laid back, she seemed very disoriented, dizzy and kept shaking her head. Any idea what this could be and if there is anything that I can do?