DISEASES OF THE HEAET AND BLOOD, ETC. 365 



lancet, and the neck has been corded. Such a thickening 

 of the blood is due to the influence of fever. It has be- 

 come sticky; it moves sluggishly in the veins, and is no 

 longer the life-sustaining, strength-giving fluid that ]N"ature 

 designed it to be. 



Such blood is very dark in color. In those diseases that 

 involve the general system, it is astonishing how thick and 

 dark the blood becomes. In cases of big head, for example, 

 we have often found the blood of a tinge even deeper than 

 a dark brown — ^in fact, almost black. 



This condition of the blood is attributable to fever, and is 

 always a feature in fistula, distemper, glanders, farcy, chronic 

 founder, hide-bound, mange, and in some of the diseases of 

 the lungs. Its existence, with very rare exceptions, is indic- 

 ative of the propriety of bleeding, and generally of its absolute 

 necessity. 



THIN BLOOD. 



There are some diseases, producing little or no fever, that 

 have a tendency to make the blood too thin and watery. 

 Such are the " scours " that affect ijiany horses, diarrhea or 

 dysentery, and other diseases that waste away the body by 

 continued defluxions. Affections of the urinary organs be- 

 long to this class. Consumption, also, disorganizes the blood, 

 making it thin and light. 



The blood, as was explained in Chapter II, is made up 

 of coagulum, or clot, and serum, or watery fluid. In disorders 

 of the kind we are now considering there is a deficiency of 

 coagulum, which is the component that gives the blood its red 

 color; and, from the excess of the thin, colorless serum, the 

 blood becomes pale and watery. In such cases, the horse, 

 instead of being bled, needs the most generous diet and treat- 

 ment, in order that more and richer blood may be made and 

 thrown into the feeble circulation. 



BLEEDING. 



Physicians, in treating the human subject, have almost 

 dispensed with phlebotomy as unnecessary, and tending to 



