Canine anal sac disorders are relatively common. The anal sacs are paired structures located on either side of a dog’s anus (the terminal end of the digestive tract through which feces is expelled). Normally, the anal sacs secrete a very smelly substance when a dog defecates, which probably acts as a form of territorial marking. When these sacs become irritated, inflamed, impacted or infected – which can occur for a number of reasons – their contents can’t drain normally, although the glandular tissue lining the sacs continue to produce the substance. The discomfort, itchiness and pain suffered by dogs with impacted anal glands can range from quite mild to extremely severe. Affected animals will be uncomfortable, at best.