I can’t recall any wound on his lip to start this problem . When I first noticed it it looked like it does now.
Last nite I went to bed thinking about it. Possibly an ant bit him . I fed him some roses from the neighbor and didn’t realize there were those big ants in there . I heard him bangin around in his house and went to look I killed all the ants 3 of them and felt around for ant bites but didn’t feel any,
However my other tought and probably the cause is fish. I would take him to the dock on his harness and hubby had some fish lying around. Cotton got curious and went to smell it. I watched and never saw him get that close tho. Not that I recall anyways. Though I really think it was a scratch from the fish fins. Perhaps when I wasn’t looking. If so tho he would have jumped and ran. Which he never did. 
Who knows. I did notice on her report he has staph as well that settled in his lip there.
His Dr. decided on shots cuz the oral stuff didn’t finish it off. This is stronger so hopefully this works. If not she will consult with another vet.
Staph tho I would think fish a likely cause. Or a bite from Ruby I missed.
Mimz Mum I left a response on your post about no more shots. Yep our turn. 
The shots were 92.00 I only had 40 to spare. The office person spoke with the vet and it became half price 50.00 there abouts. That is so sweet of her
I am going to have to send her a thank you card and an email.