22 Veterinary Medicine. 



are most commonly in the systemic circulation (osteomyelitis, 

 omphalitis, wounds, traumas) the lungs are most commonly 

 attacked, the pulmonary capillaries acting as a sieve and arresting 

 the floating infective coagula. When the primary infection comes 

 from the chylo-poietic viscera, the liver is likely to show the first 

 crop of secondary abscesses. When, on the other hand, the pri- 

 mary abscess is in the lungs, the great flow of blood through the 

 kidney renders it especially subject to secondary suppurating foci, 

 though these may form in any part of the body. 



Lesions. Pyaemia may result from a wound or abscess in con- 

 nection with which will usually be found a vein containing a 

 thrombus more or less softened or liquefied. If from a deep seated 

 injury or from osteomyelitis, the same condition is met with. The 

 thrombus and circulating blood furnish abundance of the infective 

 microbes, and at distant points, in the complimentary circulation, 

 most commonly in the lungs the arteries are found to he the seats 

 of embolism from arrested clots. The arrest always takes place 

 where the vessels are diminished by bifurcation, or the giving off 

 of a considerable colateral trunk, and the appearances will depend 

 on the duration of the embolism. If quite recent, a wedge-shaped 

 mass of tissue supplied by the vessel is ischsemic and pale, its 

 blood passing on into the veins without further arterial supply; if 

 later, this tissue forms an infarct being gorged with deep red or 

 black blood which has filtered in from adjacent anostomosing cap- 

 illaries and distended those of the exsanguine area. This area 

 becomes of a deep red or black color, consolidated by an exudate 

 of lymph, and rapidly invaded by suppuration. The microbes 

 determine suppuration and softening, first in the clot and intima, 

 and next in the outer coats of the vessel and the surrounding ex- 

 udate, so that an abscess of variable size may result. Abscesses 

 are usually smaller and more numerous in the acute forms of the 

 disease, and larger and less numerous in the more chronic. 



Ulcerative endocarditis with coagula on the valves is not un- 

 common. The spleen is often the seat of small abscesses in the 

 centre of solid exudates, with, in many cases, softening and enlarge- 

 ment of the organ. The blood tends to retain its normal bright 

 red color, and clots firmly, contrary to the usual condition in 

 septicaemia. 



Symptoms. The formation of emboli and secondary abscess is 

 usually marked by a violent rigor, lasting from a few minutes to 



