52 The Diseases of Animals 
curate method until the tenth or twelfth year. After 
this period the general appearance of the teeth and the 
bones of the head are relied upon in determining age. 
In colts, the bones of the face and lower jaw have a 
full, rounded appearance, because the roots of the teeth 
extend far into the bone. The face gradually becomes 
more concave on the sides, the lower jaw thinner from 
side to side, and the lower edge much sharper. The 
hollows above the horse’s eyes become deeper, and the 
bones more prominent, due to the absorption of fat from 
this region. Unserupulous horse-jockeys sometimes 
make a small incision through the skin and fill up this 
depression by blowing it full of air. This practice is 
commonly called “puffing the glims.” It is a deception 
that is easily recognized. As horses get older there is 
a tendency for the hair to turn gray in the region of the 
muzzle and the eyes, and there is a general appearance 
of advancing age that is difficult to describe. 
THE TEETH OF THE HORSE 
In the mature horse’s mouth, the teeth which are 
used for biting the food are twelve in number, six 
in each jaw. They are situated just within the lips, 
and are called the incisors. The molars, or grinders, 
are the large double teeth, whose function it is to mas- 
ticate, or grind, the food. There are twenty-four of 
these, six in each half of both upper and lower jaws. 
In males, there is an extra tooth called the canine, or 
“bridle” tooth on each half jaw, in the space between 
the incisors and the molars, These are sometimes found 
