643 



CHAPTER XIII. 



DISEASES OF THE MOUTH AND NASAL ORGANS. 



THE mouth of the dog is beautifully adapted for the purpose Nature meant it to serve namely, 

 as a weapon both of defence and offence. It is very capacious, and is armed with strong 

 incisors and powerful fangs, which latter are in some 'breeds such as the Dachshund and 

 Bull-dog partially recurvent, like those of the shark, this recurvency enabling him to retain a 

 firm hold of the prey he may have captured. 



The dog, like the human being, is furnished during his lifetime with two sets of teeth. The 

 first the milk teeth are all cut within a fortnight after the birth of the puppy. They are ex- 

 ceedingly beautiful and very fragile. They begin to fall out and be replaced in the following order : 

 first the front teeth or incisors go (this in from a month to seven weeks), and soon after the 

 second, third, and fourth molars fall out, and in a few months the other molars follow suit ; 

 so that in from five to six or eight months the milk teeth are replaced by the permanent. 

 These latter are forty-two in number, twenty-two occupying the lower and twenty the upper 

 jaw. The following is the correct formula as given by the highest authorities : 



Upper jaw Iricisors 6 ; Fangs i i ; Molars 6 6 = 20 "| 

 Lower jaw 6 ; i i ; 7 7 = 22 J " 



In most breeds of dogs the teeth are level ; that is, the incisors of the two jaws meet 

 when the mouth is closed, so that you cannot insert your finger-nail behind either row. But 

 some breeds of dogs are underhung, and in some the upper jaw projects. The four middle 



incisors - are called the pincers, the next four I ~ > at each side of these, the intermediates, and 

 the last four flanking these - - 1 the corners. The upper incisors are larger than the under, and 



the cutting or free edge of each incisor has on it in the young dog two or three little 

 tubercles. The middle lobe or tubercle is the first to wear ; finally they all disappear. The 

 fourth molars in the upper jaw and the fifth in the lower are the largest; and notice, too, 

 the cutting or free edge of these they are not like those of an ox or human being, they are 

 made to tear and rend, not to grind. 



The teeth of the young dog, and indeed of any dog that has been properly cared for and 

 correctly fed, are beautifully white and pearly ; one reason for this being that the crown or 

 exposed portion of the tooth is covered with enamel, not cementum. Can we tell the age of 

 a dog by looking at his teeth ? By no means correctly. The presence of the tubercles on 

 the middle incisors would lead one to infer that the animal was under three years, but their 

 absence would not prove that he was over three. The complete possession of all the permanent 

 teeth in a puppy would prove that it was over six months old, but the absence of some of 

 them would not prove him to be under. We have to remember, too, that the dog's teeth are 

 very subject to disease and to different degrees of wear and tear, according to how he is fed 

 and used. Neither by the teeth nor by the eyes can you tell a dog's age, although from the 



