Anatomical Changes; 



855 



or less enlarged liver, the substance of which is usually yellowish, 

 discolored, and may be so brittle that a rupture may result 

 (Carre & Vallee). In the intestinal mucous membrane either 

 single, roundish hemorrhages appear, or the mucous membrane, 

 especially in the large intestines, may 

 manifest diffuse hemorrhages, when 

 a more or less bloody consistency of 

 the intestinal contents is noted. 

 Hemorrhages are less frequent in the 

 stomach, but they may sometimes oc- 

 cur. The heart, with the exception of 

 the very slow cases, shows subperi- 

 or subendocardial and intramuscular 

 hemorrhages, their number and size 

 being usually in an inverse proportion 

 to the duration of the disease (in very 

 acute cases the heart appears as if 

 sprinkled with blood). The kidneys 

 and the lungs contain small hemor- 

 rhages only in acute cases, at the same 

 time there is always a parenchyma- 

 tous inflammation of the kidneys, 

 heart muscle, and the liver substance. 

 The mucous membranes of the urinary 

 bladder sometimes show hemorrhagic 

 spots of recent or older origin. 



Conspicuous and constant changes 

 are present in the bone marrow. In the 

 proximal long bones of the extremi- 

 ties, especially so in the bones of the 

 upper thigh or upper arm, the bone 

 marrow is changed, either for its en- 

 tire length or only in parts, to a dark 

 brownish-red or blackish-red mass 

 (Fig. 152). In the cases with slower 

 course only various sized circum- 

 scribed areas are found in the fat 

 marrow or this may appear normal. 

 At the same time however the spongy 

 bone marrow shows the above changes 

 or at least a reddish discoloration. The 



spongy bone marrow of the vertebrae, ribs, etc., manifests simi- 

 lar changes. Even in the most chronic cases at least small hem- 

 orrhages are found, which however appear of a peculiar ink- 

 black color if of earlier origin. This condition of the bone 

 marrow does not result from hemorrhages, but represents, as 

 in older losses of blood in general, only a regenerative process, 

 and consists in an increased activity of the blood-forming ele- 

 ments of the red marrow areas, the normal occurrence of which, 



Fig. 152. Infectious anemia. 

 Femur of a horse. Longitudinal 

 section ; « dark red area in fat 

 marrow ; b normal yellow bone 

 marrow; c diffuse dark red dis- 

 coloration of the spongy mar- 

 row ; d small dark red foci. 



