Male dog nipple

My 5 year old male white boxer has this weird thing on his nipple. It was not there yesterday (12/21/21). I put neosporin on it and out a t-shirt on him so he leaves it alone, but he did not seem bothered by me touching it at all. His nipples normally have black spots, so that black spot is his actual nipple. I will be taking him to the vet tomorrow or Friday. It looks kind of like it is peeling on the outer edges and there is no pus or scratch. I have two other dogs amd a rabbit, so I'm nervous whatever this is could be contagious. Looks about the size of a quarter. TIA

Hello!  So this lesion doesn't sound to itch?  This is a little worrying as cancer is amongst the lesions that do not itch and it may be that your vet suggests taking a biopsy in order to identify this lesion.  Other possibilities include hyperplasia, bacterial, yeast or fungal skin disease, allergy and certain infectious diseases, so we would advise showing it to a vet as soon as this is appropriate.  If your vet cannot identify the lesion immediately, they may ask to take a biopsy of the skin.  Best of luck and we'd be interested to hear how they get on.

The pictures appear to show two different lesions; how many are there?  A contact allergy may be another possibility, from lying in certain positions on different surfaces.  We are pleased to hear that you have a vet appointment booked and hopefully they will have triaged the patient in case an earlier consultation is necessary.  Best of luck and we look forward to hearing what is found.