476 HEALTH AND DISEASE 



subsequent to its occurrence, of some septic or decomposing matter. A 

 dirty Heam or lancet, a dirty pin, or dirty tow employed to bring the edges 

 of the divided vessel together, are the most likely media by which to infect 

 the wound. Inflammation of the vessel having been thus excited, the 

 blood circulating within it is induced to coagulate, and to be deposited 

 on the inflamed surface layer after layer until the passage becomes com- 

 pletely obstructed and the flow of blood along the neck on the afl'ected side 

 is arrested in its course towards the heart. 



Symptoms. — The lips of the wounded vessel are more or less tumefied 

 and separated from each other, and the parts around are swollen and 

 painful to the touch. The plugging of the vessel invariably proceeds in an 

 upward direction, where it may be felt for some distance as a hard, cord- 

 like thickening in the channel of the neck. Subsequent changes in the 

 condition of the vessel and its contents will depend upon circumstances. 

 In some instances the wound heals, the plug becomes organized, still re- 

 taining its position in the vein, with which it unites to form a solid cord. 

 Here the general health of the patient is but little impaired; since, how- 

 ever, the jugular vein is no longer able to convey the blood back from 

 that side of the head to the heart, the vessels of the face will be inordi- 

 nately distended, the brain will be somewhat surcharged with blood and 

 liable to slight functional disturbances, especially when the head is held 

 in a depending position. This danget will be materially modified after 

 a time, when compensating enlargement of the jugular vein of the opposite 

 side and its tributaries takes place, and their carrying capacity becomes 

 thereby increased. 



It must be understood that with one jugular vein spoilt the conveyance 

 of blood from the head to the heart will have to be done for the most part 

 by the other, which, in course of a little time, will widen out and accom- 

 modate itself to .the task imposed upon it. 



Animals having sufi"ered from this disease should not be turned to grass 

 or allowed to eat from the ground. The downward position of the head 

 under the altered conditions of the circulation tends to an accumulation 

 of venous blood in the vessels of the head, resulting in swelling of the 

 lips and tissues of the face, dizziness, and vertigo. 



Instead of being organized, the plug in the vein may soften and break 

 up into a pus -like matter, resulting in the formation of one or more 

 abscesses in the upward course of the swelling. These may break, empty 

 themselves, and heal, perhaps to form again and produce deep sinuous 

 wounds in the track of the vessel. The most serious consequences re- 

 sulting from jugular thrombosis occur when matter from the softened and 

 disintegrated clot finds its way into the circulation. Thereby the blood 



