Update: I gave Twist, as instructed by the vet, 120cc of the solution prescribed (mostly saline ). Have to use two 60cc syringes with large bore needles. I pinch the skin on his neck, lift it, and inject under skin. Once I got him situated on our kitchen counter, the process went smoothly and quick. He held still, thankfully.
He is eating good, but for now it's as if he's never been in our house. He remains in a back room, and is not venturing out. I feel bad, as am sure he was traumatized, having been in a cage at the vet for 3 days.
I check on him a lot during the day, and am hoping he eventually adjusts. NC