The method of judging the age of a horse is by examining the teeth,
which amount to forty when complete; namely, six nippers, or incisors,
as they are sometimes called, two tushes, and six grinders on each side,
in both jaws. A foal, when first born, has in each jaw the first and
second grinders developed; in about a week the two centre nippers make
their appearance, and within a month a third grinder. Between the sixth
and ninth month the whole of the nippers appear, completing the _colt’s
mouth_. At the completion of the first year a fourth grinder appears,
and a fifth by the end of the second year. At this period a new process
commences, the front or first grinder giving way, which is succeeded by
a larger and permanent tooth, and between two years and a half and three
years the two middle nippers are displaced, and succeeded by permanent
teeth. At three years old the sixth grinder has either made or is about
making its appearance. In the fourth year another pair of nippers and
the second pair of grinders are shed; and the corner nippers, toward the
end of the fifth year, are succeeded by permanent teeth, when the mouth
is considered almost perfect, and the colt or filly becomes a horse or a
mare. What is called the _mark_ of the teeth by which a judgment of the
age of a horse for several years may be formed, consists of a portion of
the enamel bending over and forming a little pit in the surface of the
nipper, the inside and bottom of which becomes blackened by the food.
This soon begins to wear down, and the _mark_ becomes shorter and wider,
and fainter. By the end of the first year the mark in the two middle
teeth is wide and faint, and becomes still wider and fainter till the
end of the third year, by which time the centre nippers have been
displaced by the permanent teeth, which are larger than the others,
though not yet so high, and the mark is long, narrow, deep, and black.
At four years the second pair of permanent nippers will be up, the mark
of which will be deep, while that of the first pair will be somewhat
fainter, and that of the corner pair nearly effaced. At this age, too,
the tushes begin to appear. Between the fourth and fifth year, the
corner nippers have been shed, and the new teeth come quite up, showing
the long deep irregular mark; the other nippers bearing evident tokens
of increasing wearing. At six years the mark on the centre nippers is
worn out, but there is still a brown hue in the centre of the tooth. At
seven years the mark will be worn from the four centre nippers, and will
have completely disappeared at eight years from them all. It may be
added, that it is the lower jaw of the horse that is usually examined,
and which is here described. The changes of the teeth taking place in
both jaws about the same time, but the cavity of the teeth in the upper
jaw being somewhat deeper, the mark lasts longer, though the exact
period is a matter of controversy. According to what may be considered
good authority, however, it may be stated that at nine years the mark
will be worn from the middle nippers, from the next pair at ten, and
from all the upper nippers at eleven. During all this time the tushes
(the extremities of which are at first sharp-pointed and curved) become
gradually blunter, shorter, and rounder. For further information on this
subject, the volume on the Horse, published by the Society, may be
advantageously consulted.
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