My dog opened the fridge for the first time last night and stole a lump of cheddar. I would say he had about half of a 250 gr. piece. About an hour later he vomited that and his previous meal. He has not been able to keep anything down today and he is due at the vets for castration first thing tomorrow morning. Is it normal to still be vomiting 24 hours after stealing the cheese and getting rid of it? I am inclined to put off the op. as he certainly will not be at his best after the last 24 hours and am not quite sure why he has not recovered by now. A friend mentioned he could be allergic to cheese but I have been using cubed cheese as training treats for a couple of weeks with no ill effects? What do you think and has anybody had the same happen?