EXAMINING THE TEETH 207 



3 on each side in the lower jaw ; and 12 molars, 3 on each 

 side in both upper and lower jaws, making a total of 40 or 

 42 permanent teeth in the mouth of the mature horse. 

 The colt does not have a " full mouth." 



Changes take place quite uniformly in the number of 

 temporar}'^ and permanent teeth found in the mouth of the 

 young horse, and in the appearance of the permanent teeth 

 as the horse advances in age. To determine the age of the 

 animal, it is necessary to examine and note the appearance 

 of the incisor teeth only. Permanent teeth are much larger 

 than the colt's temporary ones. 



At about the age of 2^ years, the central pair of temporary 

 incisors in both upper and lower jaws is replaced by per- 

 manent teeth, so that if there is present in the mouth 

 of the horse one pair of permanent incisors the animal 

 is between 2I and 3^ years of age. At about the age 

 of 3i years, one incisor on each side of the central 

 pair in both the upper and the lower jaw is replaced by 

 new permanent teeth, so that the presence of two pairs 

 of permanent incisors and one pair of temporary in- 

 cisors indicates that the horse is from ^i to 4^ years old. 

 At about the age of 4^ or 5 years, the remaining temporary 

 incisors are replaced by permanent teeth, so that at this 

 age the horse has a full mouth of permanent incisors and is 

 spoken of as having a " full mouth." Up to five years of 

 age there is not much difi&culty in determining the age of 

 the horse, because the temporary incisors, which are white 

 and smooth with a restriction about the neck of the tooth 

 near the gums, are not hard to distinguish from the perma- 

 nent incisors, which are much longer, broader, harder, and 

 stronger. 



The teeth of horses are constructed differently from those 



