Anal sacs or anal glands are two small pouches that are present on either side of the anus at the four o ‘clock and eight o’clock positions. They are lined with sebaceous glands and produce foul-smelling fluid that is stored in the anal sac until it is released into the anus via a small duct. They are often emptied during defecation. Sometimes, anal sac disease (ASD) occurs when sacs cannot be emptied either due to obesity, inflammation, diarrhea, or tumors. Symptoms of ASD include excessive licking, swelling, pain, and foul-smelling discharge from the anal sac.