and "big," toss
the head, and start suddenly when a tender spot is touched. If, as is
mostly the case, all the symptoms are referable to sharp corners or
projections, these must be removed by the rasp. If decayed teeth ere
found, or other serious difficulty detected, or if the cause of the
annoying symptoms is not discovered, an expert should be called.

[Illustration: PLATE IV.

AGE OF HORSES AS INDICATED BY TEETH.

Longitudinal section of left central lower incisor and cross sections of
same tooth showing table surfaces as they appear at the ages of 3, 5, 7,
9, 15, 20 and 25 years. _C_, Cement; _D_, Dentine; _E_, Enamel; _I_,
Infundibulum; _K_, Cup; _P_, Pulp Cavity; _S_, Star.]

_Toothache._--This is rare in the horse and is mostly witnessed when
there is decay of a tooth or inflammation about its root. Toothache is
to be discovered in the horse by the pain expressed by him while feeding
or drinking cold water. I have seen horses, affected with toothache,
that would suddenly stop chewing, throw the head to one side, and
slightly open the mouth. They behave as though some sharp body had
punctured the mouth. If upon examination, no foreign body is found, we
must then carefully examine each tooth. If this can not be done with the
hand in the mouth, we can, in most instances, discover the aching tooth
by pressing each tooth from without. By tapping the teeth in succession
with a hard object, such as a small hammer, the one that is tender may
be identified. The horse will flinch when the sore tooth is pressed or
tapped upon. In most cases there is nothing to be done but extract the
decayed tooth, and this, of course, is to be attempted by the
veterinarian only.

_Deformity._--There is a deformity, known as parrot-mouth, that
interferes with prehension, mastication, and, indirectly, with
digestion. The upper incisors project in front of and beyond the lower
ones. The teeth of both jaws become unusually long, as they are not worn
down by friction. Such horses experience much difficulty in grazing.
Little can be done except to examine the teeth occasionally, and if
those of the lower jaw become so long that they bruise the "bars" of the
upper jaw, they must be shortened by the rasp or saw. Horses with this
deformity should never be left entirely at pasture.

The method of determining the age of a horse by the teeth is illustrated
in Plate IV.

DISEASES OF THE MOUTH.

LAMPAS.

Lampas is the name given to a s