432 BLISTERING. 



is the sheet-anchor of the veterinarian ; yet few things are more to be reprobated 

 than the indiscriminate bleeding of the groom or the farrier. 



The change which takes place in the blood after it is drawn from the vein is 

 diligently noticed by many practitioners, and is certainly deserving of some 

 attention. The blood coagulates soon after it is taken from the vein. The 

 coagulable part is composed of two substances : that which gives colour to the 

 blood, and that in which the red particles float. These, by degrees, separate 

 from each other, and the red particles sink to the bottom. If the coagulation 

 takes place slowly, the red particles have more time to sink through the fluid, 

 and there appears on the top a thick, yellowish, adhesive substance, called the 

 buffy coat. The slowness of the coagulation and the thickness of buffy coat 

 are indicative of inflammation, and of the degree of inflammation. 



In a healthy state of the system, the coagulation is more rapid, the red particles 

 have not time to fall through, and the buffy coat is thin. These appearances are 

 worth observing ; but much more dependence is to be placed on the character and 

 change of the pulse, and the symptoms generally. When the horse is exhausted 

 and the system nearly broken up, the blood will sometimes not coagulate but 

 be of one uniform black colour and loose texture. When the blood runs down 

 the side of the vessel in which it is received, the coagulation will be very imper- 

 fect. When it is drawn in a full stream, it coagulates slowly, and when pro- 

 cured from a smaller orifice, the coagulation is more rapid. Every circumstance 

 affecting the coagulation and appearance of the blood, the pulse, and the general 

 symptoms, should be most attentively regarded. 



A great deal of mystery is associated with bleeding in the management of the 

 racer and the hunter. The labour of the turf and the field having ceased, 

 there is frequently some difficulty in preventing a plethoric state of the con- 

 stitution — a tendency to inflammatory complaints. If the horse is rapidly 

 accumulating flesh, it may be prudent to abstract blood, dependent in quantity 

 on the age and constitution of the animal. Attention to this may prevent 

 many a horse from going wrong ; but the custom that once prevailed of bleeding 

 every horse a fortnight or more after the racing or hunting season had passed, 

 is decidedly objectionable. 



As preparatory to work, bleeding is far from being so much employed as it 

 used to be. As a universal practice, when the horse is first taken from grass, it 

 now scarcely exists. It would not always be objected to, if the horse was fat 

 and full of flesh, but, otherwise, it is a custom more honoured in the breach than 

 the observance. It certainly produces very considerable effect. More rapidly 

 than any species of diet — more rapidly than any sweating or purging; it reduces 

 the condition of the horse, but, we have often thought, at the expense of those 

 essentials to life and health that cannot be easily replaced. 



BLISTERING. 



We have spoken of the effect of blisters, when treating of the various 

 diseases to which they are applicable. The principle on which they act is, 

 that no two intense inflammations can exist in neighbouring parts, or perhaps 

 in the system, at the same time. Hence we apply some stimulating acrimo- 

 nious substance to the skin, in order to excite external inflammation, and thus 

 lessen or remove that which exists in some deeper seated and, generally, not far 

 distant part. Hence, also, we blister the sides in inflammation of the lungSr-^- 

 the abdomen in that of the bowels — the legs in that of the cellular substance 

 surrounding the sheaths of the tendons, or the sheaths themselves, and the 

 coronet or the heel in inflammation of the navicular joint. 



Blisters have likewise the property of increasing the activity of the neigh- 

 bouring vessels : thus we blister to bring the tumour of strangles more speedily 



