AGASACA or Apocrine Gland Anal Sac Adenocarcinoma

Dogs and cats have anal sacs. These are two blind-ending sacs on either side of the anus located between the external and internal anal sphincter muscles. Dogs and cats may develop cancer from one or both anal sacs that will either cause some discomfort or a mass is noted on an annual vet visit incidentally. The diagnosis is made relatively easily by getting a fine needle sample for cytology.