298 A TREATISE ON HORSE-BREEDtNG. 



ing wag-on, but how much more so if the horse is hereditarily 

 predisposed to ophthalmia. In the same way we should 

 guard the horse against the cinders flying into open railway 

 cars, from the dust of a threshing machine blowing upon the 

 horses engaged in driving it, the dust of a harrow driven in 

 the same direction as the wind, the smoke of burning rub- 

 bish, etc. 



In addition to the bad. effects of insufficient, faulty, or too 

 stimulating food, already referred to, it is well to note that 

 the consumption of too much sugar is liable to induce disease 

 of the eye. This is especially likely to result from a too ex- 

 clusive diet of sorghum, or from the large admixture of mo- 

 lasses with the food. It may, indeed, be questioned whether 

 the notoriously evil effects of a diet of Indian corn on the 

 eyes is not partly due to the abundance of starch in its com- 

 position and to the conversion of that starch into sugar in 

 the system. 



THE EYE AS AFFECTED BY THE TEETH.* 



The process of teething is calculated to rouse into activity 

 a latent predisposition to disease of the eye in horses. The 

 rapid progress of teething in the horse and the completion 

 of the process at an early age determines much vascular and 

 nervous excitement about the head, and the weakest point 

 in many cases being the eyes these are too often the parts to 

 suffer. To illustrate the influence of teething it need only 

 be said that at three years old the horse acquires eight new 

 grinding teeth and four front ones. A year later he acquires 

 eight additional grinders, four front teeth and four tushes. 

 It is small wonder that at these ages the gums and soft pad 

 of the upper jaw swell; that the horse refuses his food, or 

 eats with little appetite; that he drops morsels half chewed, 

 and that he appears at times sluggish, dull and feverish. 

 Nor is it surprising that at this age the progeny of horses 

 that have suffered from recurring ophthalmia themselves 

 show symptoms of the same disease. It is this tendency to 

 diseases of the eyes during the eruption of the permanent 



* The Breeder's Gazette, Vol. I, p. 536. 



