If I take him to the vet, I have to turn him over. They won't treat 'pets' like this without a license. We were planning on taking him this thursday anyway, but if something is wrong, it doesn't need to wait.
If squirrels are lethargic, do they tend to just sit and watch, or do they want to sleep?
He has spirts of energy and then gets settled. Were you guys able to see his gums?