This trouble is of more frequent occurrence in puppies than old dogs. It is the result of the bowel telescoping upon itself. By careful manipulation of the abdomen it can be located by a long, hard swelling. The patient suffers much pain and usually whines and cries pitifully. The other symptoms are diarrhea, with blood-tinged mucus, and in the early stages vomiting. Intussusception is due to a variety of causes, such as worms, indigestion and colic, or the eating of hard substances, but as indigestion, colic and the abnormal appetite that causes dogs to eat indigestible and irritating matter are more or less the result of the presence of worms, the latter must be accepted as the primary cause. The importance of treating for them frequently is therefore apparent. In treating mild cases that have not progressed far give from one to five drops of laudanum every three hours in a teaspoonful of milk. One drop is the correct dose for a puppy two to three months old of the toy breeds and five drops is the dose for the large breeds of the age mentioned. Feed only liquid food - milk or beef tea. If there is not a decided improvement in the puppy's condition in twenty-four hours an operation should be resorted to. In the early stages it is nearly always successful and the puppy receives immediate relief. If it is postponed the operation is more difficult, on account of the inflammation, and the bowels cannot be so easily straightened. The patient should fast for twenty-four hours following the operation, after which for a few days administer only liquids.