Poor Ben, he must feel very traumatised. He may just need a little more time to sleep & get over the shock.
There are certain things that I have in my fridge or freezer that I fall back on when the dogs are obviously off colour.............
Try hand feeding him a little chicken if you have any, and perhaps some slightly warmed goats milk will get him drinking ( or cows milk as long as he is not sensitive to it )
If he continues to refuse liquids, which is the most worrying symptom, I might consider syringing a little amount of water, only a small drop at a time, into the side of his mouth.
Cavaliers......Faith, The Ginger Tank and Woody.
Japanese Chins.... Dandy, Benny, Bridgette and Hana.
Remembered with love......... Tommy Tuppence and Fonzi