Diagnosis and staging of anal sac disease is made clinically with a rectal examination. Impacted or swollen anal sacs are often quite painful and some dogs may need sedation before a thorough examination can be done. Normal anal sac fluid is clear or pale yellow-brown; thick, brown or yellowish-green secretions are typical of animals with anal sac disease.
If the inflammation of the anal sacs has led to an abscess, a large, red, and swollen area may be visible on the side of the anus. A rupture of the abscessed sac can result in the oozing of a foul-smelling liquid material.
