The anal sacs are a pair of glands found beneath the skin around the anus. These glands normally squeeze out a small amount of bad-smelling fluid during the bowel movement. When they become infected the anal area becomes irritated, inflamed, itchy and painful. Swollen infected sacs can eventually rupture and ooze bloody pus.
Signs of infected sac include scooting, butt rubbing and licking, chewing or biting at the anal area.
Your veterinarian must insert a gloved finger into the anus to express the sacs by applying gentle pressure to “milk” the contents through the normal opening in the skin.