Ditto Mandy - pen & strep or penicillan asap

Have you any large syringes or squity sports bottles ? You could try squirting some water into the side of his gum, it might encourage him - or melon

Tastes nice and is plenty juicy so will keep him a bit more hydrated than nothing.
Poor lad
Is he off his feet or still moving around ? Seem disorientated at all ?
If he's a light skinned breed and you've had some of the unseasonal warm, sunny weather it might be heatstroke - of course, there are hundreds of things it
might be, so please don't take that as a diagnosis...... just thinking out loud

Keep us posted,
Karen x