DIGESTION AND DIGESTIBILITY 31 



disease or abnormal circumstance. Thus any disease of 

 the teeth will interfere with proper mastication of the 

 food ; coarse fodder, such as hay, will be wasted ; many 

 grains will escape crushing, and therefore digestion; and 

 if nothing worse happens, the animal will lose condition 

 and be unable to do his work. Again, the presence of 

 parasites — in the form of various worms — in the diges- 

 tive tract will prevent the digestive processes going on 

 normally, will often cause diarrhoea, and in every case 

 lessen the productive value of the food supplied. Lastly 

 may be mentioned the effects of fatigue and overwork. 

 These bring about a loss of tone in the digestive 

 apparatus, a lessened secretion of the digestive juices, 

 want of power in the bowel wall, and therefore a 

 lessened use of the food materials supplied, together 

 with danger of impaction and other acute bowel diseases. 

 Extreme old age has a similar effect. 



Most horse-owners are aware of the prevalence and 

 danger of colic in horses, but not by any means all these 

 recognise that the majority of cases of colic are due to 

 one of two causes — namely (1) excessive work, or (2) bad 

 stable management, chiefly in connection with feeding 

 and watering. The legion of advertisements advocating 

 "condition," "digestive," and "tonic," powders for 

 improving the horse's digestion exist because of the 

 failure of the horse owner to recognise that a normal 

 digestion requires no improving, and, moreover, any 

 attempt to improve it by drugs and condiments will 

 result in failure, and possibly in the production of 

 disease. When the horse's digestion is out of order, 

 endeavour should be made to discover the cause, if neces- 

 sary with the aid of professional advice, and remove 

 it, and then the trouble will cease. Above all, let it be 

 remembered that the effects of a badly-arranged dietary, 



