ZoE has had lumps at the site of almost all of her puppy shots. They all went away within a week, except the rabies one, which lasted two weeks.
I don't know what size a medium gumball is...but ZoE's were the size of a dime...rabies the size of a penny. Her vet said it was fine as long as from when I notice it, each day it got smaller. If it got larger, he said to bring her in. They always progressively got smaller
