Читать книгу Special Report on Diseases of Cattle - Lowe - Страница 120

A circumscribed dilatation of an artery, constituting a tumor which pulsates synchronously with the beats of the heart, is called aneurism. It is caused by disease and rupture of one or two of the arterial coats. The true aneurism communicates with the interior of the artery and contains coagulated blood. It is so deeply seated in cattle that treatment is out of the question. Such abnormalities are ascribable to severe exertion, to old age, to fatty or calcareous degeneration, or to parasites in the blood vessels. Death is sudden when caused by the rupture of an aneurism of a large artery, owing to internal hemorrhage. Sometimes spontaneous recovery occurs. As a rule no symptoms are caused in cattle by the presence of deep-seated aneurisms, and their presence is not known until after death.

A false aneurism results from blood escaping from a wounded artery into the adjacent tissue, where it clots, and the wound, remaining open in the artery, causes pulsation in the tumor.