How many of those does he have? It just occurred to me that the one on his nose looks kind of like a hystiocytoma--puppies and young dogs grow them--you can have them removed but their usual life span on a dog is weeks to months and left alone most of them disappear. But you rarely see more than one at a time.
Early in their development most of them look kind of wart-like--have a bumpy surface which sometimes just stays like that but sometimes the surface will start to bleed before they go away.
Just so you know--Cephalexin--is a perfectly good antibiotic for a lot of skin issues but doesn't do a thing to warts nor to hystiocytomas. Go to Google and look up hystiocytomas on dogs. (because I wasn't sure I was spelling it correctly. ) And as an incidental result of doing that I'll pass along to you something I didn't know about them--they are common in young dogs of several breeds--and then they listed the breeds--guess what--Dobermans are one of the commonly affected. Ask your vet if when they were checking for cancer cells from that bump if they checked for the cells that are present in hystiocytomas--it's the same kind of test basically.
I've had them show up on my young dogs occasionally. And I've seen them on the young dogs of friends. And even though they are regarded as something that is common only in young dogs my 9 year old fawn dog grew something on his shoulder (it looked a lot like the one on your dogs nose) so I dragged him out as his vet, who was doing surgeries that day had finished up and was trying to leave for lunch. I had looked at the lump--I thought--"This looks like a hysticytoma--how weird.." His vet looked at it and said "Boy, that looks like a hystiocytoma---huh!" Then he sent a tech to find some more of our vets to look at it--the consensus was that it looked like a hystiocytoma. So instead of going to lunch, his vet laid him on a surgery table, numbed the area and removed it because he really didn't want to mess with just taking a sample if it turned out to be a mast cell of some sort.
When we got the pathology report back it was indeed a hystiocytoma--and we had a note from the pathologist asking if this was a 9 month old dog not a 9 year old dog. You really do see them mostly only on young dogs.
I'm not a vet, not even a tech but I've spent 16 years working in a vet clinic and have had Dobermans (mostly) since 1959.
So this is just a thought..
dobebug
