Red Spot at Snout

Question

Red Sore   Me & my boyfriend have 3 dogs, all about 8 years old. Well trained, well fed, get along very well together. We have a 45 pound female mutt (no clue what breed she is) that mysteriously developed a red sore on her lip. At first we thought she may have burned her face on something but there is literally nothing we could find that would've caused this. She's had it for over a week now. It doesn't look worse and she's acting and eating fine, but it doesn't look to be getting any better either. It's not getting bigger but it does look blood blistered in the center today. I'm afraid to put any anti-biotic ointment on it for fear it will get in her mouth. Any ideas what this could be? Photo attached. Thanks in advance.

Answer
This is something that a vet needs to see. There are many things that this might be,but ultimately all of them would need the care of a vet.

She needs to have this examined as soon as possible. It's not a cancer but could be something equally as vexing.

Definitely a hands-on exam is needed in this case.