ANEURISM OF THE AORTA. 



481 



The symptomatic treatment consists in making an outlet for the 

 transudates (ascites, hydrothorax, hydro-pericarditis) ; also in the 

 administration of diuretics (the cardiacs which have just been men- 

 tioned, S(][uill, acetate of potash) ; also diaphoretics and sialagogues 

 (pilocarpine) ; the drastics may also produce momentary relief. 

 General weakness should be combated with stimulants, and palpi- 

 tations with narcotics (subcutaneous injections of morphine : for the 

 horse, 0.4 to 0.6 gramme; for the dog, 0.01 to 0.05 gramme; 

 bromide of potassium, urethane, hypnone, etc.). 



[One of the best agents to reinforce the action of digitalis is the 

 iodide of potassium in small doses of 4 to 8 grammes for the horse. 

 Its effects are most remarkable when given in combination (see 

 page 366) with other drugs. Very decided improvement can be 

 seen even when used alone. — w. l. z.] 



ANEURISM OP THE AORTA. 



Etiology. Aneurism of the aorta — a circumscribed dilatation 

 of this organ — is generally the consequence of a morbid state of its 

 walls, which is itself determined by a chronic endarteritis or a mes- 

 arteritis with fatty or calcereous degeneration. Similar vascular 

 alterations are observed on the mesenteric arteries of the horse in 

 verminous aneurism^ which is caused by the Strongylus armatus 

 (see Embolic Colics). They are more rarely found to be produced 

 by the Spiroptera sanguinolenta. Traumatic and mechanical in- 

 £uences, such as violent muscular exertions, injuries, falls, may 

 produce aneurism, especially when the arteries are already the seat 

 of a degenerative alteration. At times there seems to exist a true 

 aneurismal diathesis (Raymond). 



Pathological anatomy^ Aneurisms are sacciform, discoid, or 

 cylindrical. Their volume, which is very variable, may become 

 enormous ; they may exceed a man's head in size. In true aneur- 

 ism the sac is formed by the vascular membranes ; in false aneur- 

 ism the neighboring organs (intestine, liver, etc.) constitute their 

 walls; some of these become joined to adjacent organs — to the 

 «tomach, caecum, even to the small intestine (a case observed by 

 Schutt). The most frequent are those of the anterior mesenteric; 

 but they are also found at the point of division of the aorta, on the 

 abdominal aorta, thoracic aorta, and the aortic trunk (Konhauser). 

 Ijustig has found a voluminous aneurism in the horse, which occu- 



31 



