in some children during teething, and the nervous exhaustion and 

 complaints arising therefrom, need we be at all surprised to notice, 

 at this period, the commencement of several nervous derangements 

 in the horse. 



348. Having had ample opportunities of inspecting animals, from 

 foals upwards, 1 find it very rare that any sign or symptom of chorea, 

 shivering, string-halt, or clicking occurs until the animal is rising 

 three years old. From long observation, I am, therefore, inclined to 

 think that in the irritation set up during the extensive dental processes 

 just referred to, will be found the cause and the commencement of these 

 nervo-muscular derangements, through a reflex nervous action that 

 is set up, more particularly so, when there is a hereditary tendency 

 thereto. The most critical period, therefore, in the life of a horse is 

 when it is rising three years old ; for not only are there associated with 

 it at this period the above mentioned complaints, but also strangles ; 

 though, whether the latter is partially due to extensive dentition, or 

 to the change from out-door to in-door life, or to the two combined, I 

 am scarcely able to say ; yet, I am inclined to think that teething, in 

 certain instances, has something to do with the cause. Again, at this 

 period, if the true process of dentition is not going on, there may be 

 abscesses formed at the root of the tooth, or in the sinuses, with 

 disease of the alveolar processes — more particularly^ in the upper jaw— 

 and ending in softening and degeneration of the bone ; or bony tumours 

 may form on the tooth itself. {Plate XXVIII., No. 3, represents a 

 tumour on the crown of the fourth upper, or first permanent molar 

 tooth, due to extensive inffammation and degeneration of the bones of 

 the face of a three-year-old filly.) 



349. Shortly after I conmienced practice, a three-year-old cart colt 

 was brought to me in a very emaciated condition, for the purpose of 

 having its lampers burnt or cut. On looking into the mouth, I saw 

 the crowns of the first and second temporary pre-molars sticking on 

 the top of the permanent teeth which were well up above the gums. 

 Here, then, was the cause of the poor condition of the animal. I 

 could not remove these shells with my fingers, and, having no instru- 



