Q. MY dog has a lump on her back which is soft at first, but now it became hardened and is spreading to the lower back. I notice 3 more soft lumps. It
DAVID ELBEZE, DVM, MRCVS
A. Multiple lumps that are growing fast is not good news usually. If it appeared pretty much overnight it could be an allergic reaction creating "bumps" that spread all over, but according to your description I am suspecting it didn't appear that fast.
It is most likely a fast growing multiple tumor, I couldn't tell you what type as it has to be checked by the vet or a pathologist/histologist at the lab. Most fast growing tumors are malignant although there are a few that could be benign as well.
I recommend taking her to the vet, they will perform a needle aspiration and will attempt to diagnose the type of tumor and treat it accordingly.