30 INTRODUCTION. 



regard to these causes, examples will be given in the order 

 above stated. 



The first is looked upon as the cause of the many dis- 

 eases which take on an epizootic form. The second, rusty 

 straw, and musty hay and corn fed to animals with weak 

 stomachs. Third, riding too far and too fast, overloading, 

 etc. Fourth, animals drinking out of leeden troughs, 

 where pieces of old iron may be lying in the bottom. In- 

 oculation by the virus from a glandered horse, are illustra- 

 tions of animal poisons, zumins, or ferments. (See Glan- 

 ders.) Fifth, a horse with point of hock inclined forward, 

 which is the originator of curb. Sixth, an old horse or 

 cow, with no teeth to chew its feed. Seventh, taking an 

 animal from a warm and comfortable stable, and exposing 

 it to a cold, north-eastern storm. Eighth, a flat forehead, 

 transmitted from parentage, thus preventing a full develop- 

 ment of the brain where the optic nerve is given off from 

 the brain, thus insuring blindness about the seventh or 

 eighth year, and sometimes earlier. None need be told of 

 the disposition of the coarse-bred Canadian horse to be- 

 come affected with disease of the bones, mostly in the form 

 of ring-bone, (which see.) Ninth, stone in the bladder, 

 and calculi in the bowels. Tenth, besieged garrisons, for- 

 tresses, Avhen crops have failed, and famine. 



HOW TO OBSERVE DISEASES. 



We are sometimes asked how it is that we know so ex- 

 actly what the disease is that this or that animal is affected 

 with, as it cannot speak and narrate its ills an(^ its aches. 

 To this question we might repeat a common truism, " A 

 shut mouth tells no lies ;^^ therefore, nobody is deceived. 

 Nature has but one set of weights and measui^es, and these 



