252 



DISEASES OF CATTLE. 



equal, the strong, vigorous races are the least predisposed to the mal- 

 ady, and in this respect the compact form, the healthy coat, the clear 

 eye, and the bold, active carriage are desirable. Even the color of 

 the hair is not unimportant, as in the same herd I have found a far 

 greater number of victims among the light colors (light yellow, light 

 brown) than among those of a darker tint. This constitutional pre- 

 disposition to indigestion and diarrhea is sometimes fostered by too 

 close breeding, without taking due account of the maintenance of a 

 robust constitution, and hence animals that are very much inbred 

 need to be especially observed and cared for unless their inherent 

 vigor has been thoroughly attested. 



The surroundings of the calf are powerful influences. Calves kept 

 indoors suffer to a greater extent than those running in the open air 

 and having the invigorating influences of sunshine, pure air, and exer- 

 cise; but close, crowded, filthy, bad-smelling buildings are especially 

 causative of the complaint. The presence in the air of carbon diox- 

 ide, the product of breathing, and of the fetid gaseous products of 

 decomposing dung and urine diminish by about one-fourth of their 

 volume the life-giving oxygen, and in the same ratio hinder the aera- 

 tion of the blood and the maintenance of vigorous health. Worse 

 than this, such fetid gases are usually direct poisons to the animal 

 breathing them ; for example, sulphureted hydrogen (hydrogen sul- 

 phide 2 SH 3 ) and various alkaloids (ptomaines) and toxins (neutral 

 poisonous principles) produced in the filth fermentations. These 

 lower the general health and stamina, impair digestion, and by lead- 

 ing to the accumulation in stomach and bowels of undigested mate- 

 rials they lay the foundation for offensive fermentations within these 

 organs, and consequent irritation, poisoning, and diarrhea. They 

 further weaken the system so that it can no longer resist and overcome 

 the trouble. 



The condition of the nursing cow and her milk is another potent 

 cause of trouble. The food of the cow is important. The influence 

 of this is shown in the following tables: 



Becquerel and Vernois. 



