Introduction

Anal sac disorders are relatively common in dogs, especially in small breeds. The anal sacs are paired structures on either side of a dog’s anus that normally secrete a very smelly substance during defecation, probably as a form of territorial marking. When these sacs become irritated, inflamed, impacted or infected – which can occur for a number of reasons – the contents of the sacs are unable to drain normally, which causes affected animals to suffer discomfort, itchiness and pain that can range from quite mild to extremely severe.

Symptoms of Anal Sac Problems

Dogs with anal sac disorders usually show signs of physical discomfort at or near the area around their anus (called the perianal or perineal region). The affected area may be swollen and red, and there may be visible blood and pus on fecal matter or around the anus, especially when an anal sac abscess has ruptured. Signs suggesting that something is wrong with one or both of a dog’s anal sacs may include all or some of the following:

These symptoms are caused by the pain, itchiness and general discomfort that accompanies anal sac disorders. If tumors are present, owners may (or may not) notice a visible mass or bulge near their dog’s anus. Owners often report an unpleasant "fishy" odor around their dog’s perianal region and possibly around its mouth (from the dog’s licking and biting at its rear end).

Dogs At Increased Risk

Small breed dogs develop anal sac disorders more commonly than do large breeds – particularly Miniature Poodles, Toy Poodles and Chihuahuas. Overweight animals are at a higher risk, as well. Female dogs of advanced age seem particularly predisposed to developing anal sac tumors, which may or may not be malignant or visible to the naked eye. Dogs suffering from chronic diarrhea and those with soft feces and poor rectal muscle tone are predisposed to anal sac problems.