6 Veterinary Medicine. 



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 be 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 ischaemic 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 

 an hour and which may be repeated at irregular intervals, serving, 

 in some measure, to distinguish pyaemia from septicaemia. The 

 temperature rises with the rigor, (102 to 105 ) but shows marked 

 remissions especially in the morning, when it may not exceed the 

 normal, and rising again with the recurrence of chill or staring 

 coat. The pulse is usually encreased in frequency even during 

 the remissions and is soft and compressible. Remissions may be 

 attended by profuse perspirations or even, in the advanced stages, 



