Sooo sorry - wish I had some advice
Maybe he didn't eat at all, or drink a lot last night, with all the stress going on?
Oh boy can I sympathise! Was actually thinking of furry ones last night.
Had mid to large sized dogs who'd try to
force their ways into small, confined spaces in which they couldn't fit ... trying to crawl under
US wherever we'd be sitting ...
no treat could pacify them.
Had a large dog open a cubbard (using his nose & paws), knock all the canned goods out of the way, and tried squeezing himself in there. One got stuck under a low-rise bed once, trying to force his big body under it.
One would even run into the bathtub
-- and this was a dog who, we couldn't mention the "B-Word" around him normally!
(Always knew when a thunderstorm was on the horizon, without benefit of professional forecasters, too, because the dogs would "start" early -- no matter what it looked like outside at the time.)
Oh, we did find some "surprises" later on. Poor things were so scared in their hiding spots that they apparently just couldn't "hold it".
Understandably, asking to go out, or accepting an offer to, weren't on their list of options.