244 BUREAU OF ANIMAL INDUSTRY. 



RUPTURE OF AN ARTERY. 



Endarteritis, with its subsequent changes in the walls of arteries, is 

 the primar}' cause of rupture in the majorit}^ of instances. The rup- 

 ture may be partial, involving onlj^ one or two coats, and will then form 

 an aneurism. If complete, it may produce death when it involves a 

 large vessel, especially if it is situated in one of the large cavities per- 

 mitting an excessive escape of blood. Rupture may be produced by 

 mechanical violence or accident. 



Sym^^toms. — In fatal rupture associated with profuse bleeding, the 

 animal becomes weak, the visible mucous membranes become blanched, 

 the breathing hurried or gasping, pupils dilated, staggering in gait, 

 syncope, death. When the hemorrhage is limited, the symptoms may 

 not become noticeable; if it is near the surface of the bodj" a round or 

 diffuse swelling or tumor may form, constituting a hygroma. If the 

 rupture is associated with an external wound the bleeding arter}- should 

 be ligated, or where a bandage is applicable, pressure may be applied 

 by tight bandaging. As a secondary result of rupture of an arter}- we 

 may have formation of abscess, gangrene of a part, etc. 



Treatment. — When rupture of a deep-seated artery is suspected, large 

 doses of fluid extract of ergot may be given to produce contraction of 

 the blood vessels. Taimin and iron are also useful. The animal should 

 be allowed to have as much water as he desires. Afterwards stimu- 

 lants and nourishing food are indicated. 



THROMBUS AND EMBOLISM. 



B}^ thromhosis is generall}^ understood the partial or complete closure 

 of a vessel by a morbid product developed at the site of the obstruc- 

 tion. The coagulum, which is usually fibrinous, is known as a throm- 

 hus. The term emholism designates an obstruction caused b}^ anj' body 

 detached and transported from the interior of the heart or of some 

 vessel. Thrombi occur as the result of an injuiy to the wall of the 

 vessel or may follow its compression or dilatation; they ma}^ result 

 from some alteration of the wall of the vessel b}^ disease or by the 

 retardation of the circulation. These formations ma}^ occur during 

 life, in the heart, arteries, veins, or in the portal S3'stem'. When a 

 portion of fibrin coagulates in one of the arteries and is carried along 

 by the circulation, it will be arrested, of course, in the capillaries, if 

 not before; when in the veins it may not be stopped until it reaches 

 the lungs; and when in the portal system the capillaries of the liver 

 will prevent its further progress. The formation of thrombi may act 

 primarily by causing partial or complete obstruction, and, secondarily, 

 either by larger or smaller fragments becoming detached from their 

 end, and by being carried along b}^ the circulation of the blood to 

 remote vessels, embolism; or by the coagulum becoming softened and 



