DENTAL INDICATIONS OF THE AGE OF A HORSE. 221 
During the long period which the horse is subjected 
to teething, it is surprising how little the animal has suffered 
from it, and hardly a day of his valuable services will have 
been lost. In some instances heat and swelling of the gums 
take place, but this can easily be removed by scarification. 
Here then we have an example of the wisdom and perfec¬ 
tion of the works of creation; were the horse to suffer as 
much as the human being, he would not be able to chew his 
food for weeks, and must consequently fall off in flesh. 
Dogs are liable to convulsions while cutting their teeth, and 
many even die during this process. 
At seven years the marks in the four centre incisors are 
worn out, and are speedily disappearing in the corner ones. 
The tushes are now undergoing an alteration of form; they 
are rounded at the point and edges, but still inflated out¬ 
wardly, and beginning to round inwardly ; the inner edge of 
the corner teeth is on a level with the outer, in consequence 
of wear. Sometimes a notch is observable in the upper 
comer teeth. (See plate v. fig. 1.) 
At eight years old all the marks on the teeth of the lower 
jaw will be obliterated, and will be on a level at the 
surface ; their form is changed, they assume an oval shape, 
and the cavity is altered into an elongated transverse pro¬ 
trusion of enamel, which is the termination of the central 
enamel, or funnel next the root. (Plate v. fig. 2.) After 
this period it is the practice to examine the nippers of the 
upper jaw, and to draw deductions as to the age of the 
horse; because, for years after the marks have become ob¬ 
literated in the lower jaw, traces of them exist in the upper 
jaw. This is in consequence of the enamel which occupies 
the pit in the centre of the tooth not being elevated to a 
level with the general surface, so that there is a greater depth 
to be worn down in order to rub it off; and besides, the 
