THE CIRCULATORY SYSTEM. 223 



latter anatomical point shows why obliteration of the vessel, 

 which may result from phlebitis, is less likely to interfere 

 with the grazing capabilities of an ox than of a horse. 

 The changes which take place in the inflamed vessel are, 

 roughening of the coats with exudation from them, stag- 

 nation of the blood, coagulation, and organisation of the 

 clot ; abscesses also form along the course of the vessel. 



Treatment consists in general and local antiphlogistic 

 measures, and subsequently blisters along the course of 

 the affected vessel. Embolic pneumonia may result from 

 this (see 'Veterinarian,^ vol. xii, p. 717). 



Thrombus of veins has been observed. Sucking of 

 air into the heart through the jugular, and the occurrence 

 of concretions, have not been recorded in bovine practice 

 in this country. 



Rupture of Veins, as a result of lacerated and incised 

 wounds, is not unfrequent, and sometimes this lesion 

 follows injury of other kinds. Thus, Gamgee observed, 

 in Italy, cases of rupture of vena azygos to be very fre- 

 quent in animals destroyed by "pithing^^ between the 

 atlas and axis. On this point Professor Maffei told him 

 that he noted the ruptures in 57 out of over 3000 oxen 

 and cows killed in the way indicated. The ruptures took 

 place at various parts of the vessel, and the extravasated 

 blood trickled between the laminae of the mediastinum or 

 beneath the parietal pleura (' Domestic Animals,^ p. 360, 

 second division). Wounds of veins, denoted by free and 

 even flow of dark blood, are not serious, since it is impure 

 blood which is lost ; the escape is less rapid, and its 

 " welling character facilitates coagulation, whereby nature 

 temporarily repairs the lesion.^^ 



A remarkable case of rupture of the jugular has been 

 recorded by Mr. Hill, of Wolverhampton ('Veterinary 

 JournaV 1880, vol. i, p. 291). 



Varicosity is undue distension of a vein, giving it a 

 saccular character. It depends upon any debilitating 

 influence temporarily affecting the wall of a vein. 

 It is most frequent in those which pass from important 

 organs. Thus, it affects the veins of the udder of the 



