96 DISEASES OF CATTLE. 



In many instances ligating the vessel is necessary. A ligature is a 

 piece of thread or string tied around the vessel. Ligating is almost 

 entirely confined to arteries. Veins are not ligated unless very large 

 (and even then only when other means are not available) on account of 

 the danger of phlebitis or inflammation of a vein. The ligature is tied 

 around the end of the artery, but in some instances this is difficult, and 

 it is necessary to include some of the adjacent tissue, although care 

 should be taken that a nerve is not included. To apply a ligature it is 

 necessary to have artery forceps (tweezers or small pincers may suffice) 

 by which to draw out the artery in order to tie the string around it. 

 To grasp the vessel it may be necessary to sponge the blood from the 

 wound so that the end will be exposed. In case the end of the bleeding 

 artery has retracted, a sharp-pointed hook called a teiiaculum is used 

 to draw it out far enough to tie. The ligature should be drawn tightly 

 so that the middle" and internal coats will be cut through. 



Another method of checking hemorrhage is called torsion. It consists 

 in catching the end of the bleeding vessel, drawing it out a little, and 

 then twisting it around a few times with the forceps, which lacerates 

 the internal coats so that a check is effected. It is very effectual in 

 small vessels, and is to be preferred to ligatures, because it leaves no 

 foreign body in the wound. A needle or pin may be stuck through 

 the edges of a wound, and a string passed round between the free ends 

 and the skin (Plate xxvui, Fig. 10), or it may be passed round in the form 

 of the figure 8, as is often done in the operation of bleeding from the jug- 

 ular vein. 



ARTERITIS. 



Inflammation of arteries is of rare occurrence in cattle, and requires 

 no more than mention here. 



DEGENERATION OF THE COATS OF ARTERIES. 



Three kinds are recognized: (1) Calcareous degeneration, in which 

 phosphate and carbonate of lime are deposited in the middle coat of an 

 artery; the calcification may extend to the external and internal coats; 

 it is associated with old age; (2) cartilaginous degeneration, affecting 

 small arteries; (3) fatty degeneration, usually met with in cases of fatty 

 degeneration of other parts. 



ANEURISM. 



A circumscribed dilatation of an artery, constituting a tumor which 

 pulsates synchronously with the beats of the heart, is called aneurism. 

 It is due to disease and rupture of one or two of the arterial coats. The 

 true aneurism communicates with the interior of the artery, and con- 

 tains coagulated blood. They are so deeply seated in cattle that treat- 

 ment is out of the question. Death is sudden when due to the rupture 



