Well one of my cats had this and the vet told us it was cancer and had to put her don or get expensive surgery like $ 400.oo
My 1 Year Old Cat Has A Lump Under His Jaw That Seems To Be Growing. What Could This Be?
Is the lump bleeding? See if you can check in your cats' mouth to see if there might be a decaying tooth. It could be an abscess from a tooth or a cat bite.