All dogs have two anal glands situated below the anus and connected by ducts to an opening in the rectal wall. Sometimes abnormalities occur associated with the glands which can cause great discomfort.
Small dogs suffer from an acute infection of the lining of the anal sac. The skin over the gland be comes inflamed and swollen.
Sometimes the skin becomes pointed and ruptures, releasing blood-stained purulent material and leaving a deep opening into the gland. Often it is necessary to surgically drain the swelling.
Large dogs more commonly suffer from a chronic infection of the anal sacs, which seems to cause the dog more irritation than pain.
Treatment of these infections is attempted firstly by sedating the dog, irrigating the interior of the sac and packing it with an antibiotic ointment. Sometimes the lining of the sac is so thickened that this procedure produces only temporary relief.
In stubborn cases removal of both anal glands is carried out.
Occasionally, either through a blocking of the opening of the ducts or because the contents of the glands become thicker than normal, the glands can become overdistended. These cases are not associated with an infection, but should be treated without delay.
The dog attempts to empty the glands by rubbing its anus vigorously, but if this is unsuccessful the glands should be gently evacuated, which is best done by a veterinarian.
Diet may play a part in the development of such infections. Foods that produce a bowel movement that is very soft tend not to distend the tissues of the anus and thus do not lead to the regular natural emptying of the contents of the gland.