Hi Bev. Poor Arnie. Sorry I can't remember how old he is.
Is he drinking? That's the most important thing really.
Is he eating anything at all? Perhaps best to stick to bland food for today; chicken and rice, that sort of thing.
Does he seem to be in pain?
Have a look at his gums, do they seemtobe a nice pink colour or are they pale?
If in any doubt at all, do call your vet for advice. But if all else seems ok, then just stick to bland food for today and keep an eye on him.
Hope he is better soon.