Can anyone give me some advice? Just in the past hour I noticed Mikko had some swelling on both sides of his muzzle, right where his whiskers are. One side is more swollen than the other - looks like he has a mini golf ball in there or something!

The swelling just came out of nowhere, it was not there when he got up this morning. He is acting fine, breathing normally, and does not seem to be bothered by it. I checked the skin for any kind of a bite mark or some other indication of the cause... also checked his gums/teeth and everything looks pink and healthy. We have just started transitioning him to a new food over this past week, and this did occur after he had breakfast this morning, so it might be an allergic reaction to that.

Anyway, I would have just taken Mikko to the vet, but being that it's July 4 all the vet offices are closed in town and the next option is the animal ER hospital 45 minutes away... the fee alone is $100 which I'd like to avoid if at all possible! If he was in any sort of distress I would take him there in a heartbeat, but talking to the ER Vet on the phone, she said they said Mikko could have Benadryl but they don't want to give me a dosage over the phone without seeing the dog, which I understand. Can anyone recommend a dosage of Benadryl? I read online that it's 1mg per pound of body weight, can anyone confirm that or have any other recommendations? Mikko is 25 pounds, he's 1 year, 2 months old and otherwise very healthy!

Thanks in advance for any help you can offer, I really appreciate it!!