478 



HEALTH AND DISEASE 



of the bone. When in the vessel they excite irritation in the walls, 

 resulting in inflammatory softening, and the pressure of the blood from 

 within acting upon a yielding surface results in dilatation or aneurism. 

 At the same time the existing endarteritis provokes fibrinous deposit on 



Fig. 196. Aneurism of the Aorta 



the inner surface of the vessel, tending to its more or less complete closure. 

 As a result of this, the intestines fail to receive their proper amount of 

 blood, on account of which diarrhosa is induced and prostration follows. 



ANEMIA 



Anaemia is a term employed to denote a condition of the blood in 

 which there is a deficiency of iron, an element essential to the formation 

 of red blood cells, deficiency in which results in poverty, weakness, and 

 general malaise. 



The causes of anaemia are numerous. Chief among them may be 

 mentioned insufficient or improper food, close confinement, impure air, 

 specific disease, chronic discharges, hemorrhage, the action of lead and 

 other deleterious agents in the food or water, and parasitism. In the 

 case of young horses at grass, the first and last named are perhaps the 

 more frequent, while stabled animals suffer greater risks from bad hygienic 



