As we have seen before, the young eat has twenty-six teeth, which it changes at about six months of age for thirty permanent ones. This change of teeth is frequently attended by considerable irritation of the gums, and pain, which interferes with the animal's eating, and may cause some little fever or produce a slight diarrhoea. It also gives the breath of the animal an offensive odor. The mouth should be examined, and any teeth which are loosened should be picked out with a pair of forceps, and the mouth sponged out with some listerine, which can be done by tying a small sponge on the end of a stick, or by using a large camel's-hair brush.

In old cats, as the teeth become worn, and especially in cats which are constantly fed with soft food and do not have an opportunity of rubbing their teeth clean by catching natural prey or using them on hard substances, there occurs a deposit of tartar around the roots of the teeth, which causes ulceration of the gums, and sometimes necrosis of the jaw-bone itself.

This is very painful, interferes with the animal's eating, and produces an offensive odor. The mouth should be very carefully examined; any loosened teeth should be pulled, and the others should be cleaned with a small scraper. The gums should then be well washed with lis-terine. Such a mouth cannot be cured rapidly, but requires attention every week or two for some little time.