We Have A Rottweiler And Is 8. She Has Fatty

We have a Rottweiler and is 8. She has fatty tumors on her chest. The vet said not to worry. She today was fine earlier but now won't lay down and her stomach seems a little hard. We were wondering what might be wrong. Does it sounds like that "Bloating" big dogs can have or maybe one of the tumors pushing on her shoulder. She is eating fine and has urinated and pooped.