An uncommon chronic infectious condition caused by an ANAEROBIC micro-organism, Actinomyces israelii, that often occurs as a COMMENSAL on the gums, teeth and tonsils. Commonest in adult men, the sites most affected are the jaw, lungs and intestine, though the disease can occur anywhere. Swellings develop which discharge an oily, thick pus containing yellowish (‘sulphur’) granules. A slowly progressive condition, actinomycosis usually responds to antibiotic drugs, but improvement may be slow and surgery is sometimes needed to drain infected sites. The disease also occurs in cattle, where it is known as woody tongue.