54 The Diseases of Animals 
are up “in wear” at three years. The lateral incisors 
are shed at three and a half years and the permaneut 
ones are up and in wear at four years. The corner 
incisors are shed at four and a half and the per- 
manent ones are up 
and in wear at five. 
(Fig. 17). 
The molars are 
erupted and replaced 
ax follows: The 
fourth molar on each 
jaw (which is always 
a permanent molar) 
is erupted at ten to 
twelve months; the 
fifth permanent mo- 
lar, at two to two 
and a half years, 
and the sixth usually 
at four and a_ half 
to ‘five. The first 
und second molars, 
which are  tempo- 
rary, are shed and re- 
placed by permanent 
ones at two to two and a half years of age. The third 
temporary molar is replaced by a permanent one at about 
the age of three and a half years. In males, the canine 
or “bridle” teeth are erupted at about four and a half 
years of age. A five-year-old colt has a “full mouth” 
of permanent teeth (Fig. 18), and at this age 
Fig. 17. Horse’s teeth at four years of age 
Fig. 18. Horse’s teeth at five years of age 
