Neck mass?

[Ann in NH]

Looks like we're going to the vet. Similar growths have been lipomas on myself and my dog, however this would be rather large for a lipoma. On the optimistic side, it's definitely round, medial and subcutaneous. There are no organs in that location of which I'm aware. I can't say it came up suddenly but it surprised the heck out of me to find it yesterday so believe it was fast. I was stung yesterday in front of where he's standing in the photo so possibly a bee sting? though it's not hot or tender and given it's size that seems unlikely.