My mom's dog was recently diagnosed with cancer after a large lump appeared in his leg. The doctor put him on a steroid to try and shrink it as much as possible before attempting a surgery. The surgery will roughly cost $1,300. My mom has been a little down on her luck in recent years due to medical issues of her own, including a bout of diverticulitis in which a portion of her stomach had to be removed, and she was out of work for a considerable amount of time.