In rabbits and cats in which a hemorrhagic anemia has been produced, the hemoglobin is regenerated much more slowly than the red corpuscles, but the index, relative to the red corpuscles, never rises above one. The resistance of the corpuscles is not increased. In erythrocytes developing in the bone marrow, the nucleus of the erythroblasts seems to lose its chromatin, but is apparently not extruded. Punctate basophilia of the erythrocytes is a common feature and seems to result from a diffusion of nuclear chromatin through the cell. Extramedullary myeloid metaplasia is generally slight, but in moderately severe and long continued anemia from bleeding it may be very extensive. Lipemia usually occurs when the blood is reduced below a certain limit. The greater part of the fat in the serum can be extracted with ether and is stained by osmic acid. Extensive fatty infiltration of the organs may occur and also widespread necrosis in the central parts of the liver lobules. Pigmentation of the internal organs is usually only slight, but may be considerable, particularly in the spleen.
Although there are minor differences, all the essential features of anemia produced by toxins can be reproduced by hemorrhage.