248 



or else forming an additional coat to the aorta or other large vessels 

 without producing much obstruction. Thrombi, in some instances, 

 soften in their centers, and are then observed to contain a pus-like 

 substance. If this softening has extended considerably an outer shell 

 or cyst only may remain. The sources of danger exist not only in the 

 interruiDtion of the circulation of the blood, but also in a morbid state 

 of the system, produced by the disturbed nutrition of a limb or organ, 

 as well as the mingling of purulent and gangrenous elements with the 

 blood. 



Treatment. — The urgent symjjtoms should be relieved by rest, stim- 

 ulants, and the use of agents which will act as solvents to the fibri- 

 nous clots. Alkalies are si3ecially useful for this i^urpose. Carbonate 

 of ammonia may be administered in all cases of thrombus, and should 

 be continued for a long time in small doses several times a day. In 

 cases of great debility associated Avith a low grade of fever, stimulants 

 and tonics, and nitro-muriatic acid as an antiseptic, may be bene- 

 ficial. 



DISEASES OF VEINS — PHLEBITIS. 



Inflammation of veins may bo simj)le or diffuse. In simple phle- 

 bitis the disease of the vein is confined to a circumscribed or limited 

 portion of a vein ; in diffuse it involves the vein for a long distance ; 

 it may even extend from a limb or foot to the heart. 



Causes. — Phlebitis may be induced hy contusions or direct injuries, 

 an extension of inflammation from surrounding tissue, as in abscess, 

 formation of tumor, or malignant growth. It is often due to embolism 

 of infective material, gangrenous matter, etc. Blood-letting from the 

 jugular vein is occasionally followed by dangerous phlebitis. 



Symptoms.— T\\(i symptoms vary according to the extent and 

 severity of the inflammation. In most cases the vein is swollen, 

 thickened, and indurated to such a degree as to resemble an artery. 

 A diffused swelling, with great tenderness, may extend along the 

 affected vessel and the animal manifest all the symptoms connected 

 with acute fever and general functional distiirbance. 



Pathology. — The disease is only serious when large veins are 

 affected. The coats undergo the same changes as in arteritis, clots of 

 blood and lymph plug the inflamed vessel, and if the inflammatory 

 process continues these are converted into pus, which ruptures the 

 vessel and produces a deej) abscess; or it may be carried away in the 

 circulation and produce metastatic abcess in the lungs or other remote 

 organs. In mild cases the clots may become absorbed and the vessel 

 restored to health. Phlebitis in the course of the veins of the limbs 

 frequentl}^ leads to numerous abscesses, which maj" be mistaken for 

 farcy ulcerations. A very common result of phlebitis is an oblitera- 

 tion of the affected portion of the vein, but as collateral circulation 

 is readilj^ established this is seldom of any material inconvenience. 



