Its goes from just behind where a girth would go, to her tits.... it's about 12" wide and 3+" deep!!!! The lady I board with said it could be edema?? and said that it's connected to heart failure! The vet will be here tomorrow, but does that sound possible???? It literally showed up within 24-36 hours!!! I have owned her for 16 years and she has never had this! she'll be 29 next month! Any ideas???? I am just a little freaked.