Anal Sacs. Hernia

Diseases Of Different Organs

Anal Sacs

Sometimes known as anal glands, these should not be confused with the tiny perianal glands which may develop into tumours. Anal sacs are the two pockets on either side and below the anus; they are also found in cats and foxes and are the source of the powerful odour of the skunk. The secretion from these sacs contain a viscid, fatty substance with a pungent, penetrating and sickly smell. Recent research has shown that the fluid changes in consistency through the year and when a bitch is in oestrus, and normal secretions are part of the communication system between dogs. Anal sacs are often evacuated forcibly in stressful situations, as when a nervous dog is handled by a stranger.

Anal sacs sometimes become impacted with their own secretion, causing first irritation, then pain. The dog pays more attention to its rear end, at the start gnawing away at the area around the tail root. The owner suspects the presence of fleas, which may well be correct, but the dog’s behaviour is also characteristic of anal sac inflammation.
In the second stage, the dog scrapes its anus along the ground, often interpreted as evidence of worm infestation; this is rarely the reason for such characteristic behaviour, although worms may also be present. In clipped breeds, anal sac impaction may occur after a grooming, presumably because small lengths of hair block the anal ducts. More rarely and more painfully, a grass awn may have a similar effect.

Evacuation of the anal sacs is a relatively simple, if smelly procedure, but it should not be carried out unless there are signs of impaction. Unnecessary emptying of anal sacs is likely to result in chronic inflammation and increase the chances of further impactions. Anal sacs are best expressed by the veterinarian who can establish the reasons for impaction. Most anal sac conditions are related to chronic low-grade infections which need additional treatment, in extreme cases involving removal of the anal sacs.


This is a rupture of one body cavity into another or into a space under the skin, seen most commonly in dogs at the umbilicus or navel. If the small opening at the umbilicus does not close at the time of birth, some of the fat normally located just inside the abdomen may protrude and show as a small painless swelling. It rarely causes any problems, but occasionally umbilical hernias are large enough to contain vital organs such as the bowel, which may become trapped and its blood supply threatened. The swelling is painful, irreducible, and needs surgery without delay. Another common hernia is in the groin; in bitches it may contain the uterus in pregnancy. Other hernias may result from severe blows such as in traffic accidents. The abdominal contents may be pushed into the chest by way of a diaphragmatic or hiatus hernia.

Professional advice is needed with all hernias, and radiography may be the only way to establish an accurate diagnosis and the extent of the internal disarray. Extensive surgery is almost always necessary to repair damage caused by external forces. Perineal hernia may cause the abdominal contents to be pushed into the perineal region just below the anus. This seems to occur in closely docked dogs, possibly because the musculature round the tail is too weak to maintain the integrity of the perineum.

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