Fatty growths
My friends Rott/Dobe mix had them and it was bad. They had them removed because of the location they were in. I don't have all the facts because it has been so long, but one was huge on the inside and the recovery was awful. The dog is still here, but older now. Some of these tumors have grown back, but he's so old now they chose just to keep an eye on him. Any troubles and he will adventually be helped to the bridge. I know looking at him you would think he was miserable, but he is still quite happy and active despite arthritis. He's full of small, but noticeable bumps. One breeder I contacted said that one of her lines had them bad so she didn't breed that line anymore. when I asked how many times she bred that female/line she said 6 times. BAD! I kept looking. So, I assume this a hereditary or genetic thing. I'm sorry I don't know more about them, my friend, just called them fatty tumors. I hope all goes well with your Rocky. Good Luck!