54 



The Diseases of Animals 



Fig. 17. Horse's teeth at four years of age 



are up "in wear" at three years. The lateral incisors 

 are shed at three and a half years and the permanent 

 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 

 as 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 

 and 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. 18. Horse's teeth at five years of age 



