So sorry to hear about your little dog. Hope he feels better soon.
Our Malamute mix was stung on and in his mouth when he was a puppy, he was chasing bees and unbeknown to us tried to eat one. His face swelled up like a balloon, it happened very late in the afternoon and it didn't show effect 'til later in the evening. I rang the emergency vet and they said to ice it and watch his breathing. His breathing was fine and by the next morning the swelling was down, thanks to a pack of frozen peas and constant monitoring. But, I do believe some dogs (like people) can become very sick with beestings.