138 INFECTIOUS DISEASES DUE TO PROTOZOA 

 Table XLI. — Number of Trypanosomes in the Blood (After Sauerbeck) 



Changes in the blood. — The disease is a progressive anemia. 

 Bruce reported a diminution of red corpuscles in one horse from 

 5,000,000 to 3,800,000 and in another case from 5,500,000 to 

 2,500,000. The red corpuscles decrease while the parasites be- 

 come more numerous. As low as 848,000 red corpuscles are 

 reported in the dog on the day of death. Erythroblasts are often 

 present. Schilling found a reduction of red corpuscles to 2,270,000 

 and of hemoglobin to 25%. The red corpuscles lose the power 

 of forming rouleaux and form clumps; the serum of such blood 

 mixed with normal blood of the same species of animal caused the 

 red corpuscles to clump (Kanthack, Durham and Blandford). 

 According to Kanthack, Durham and Blandford leucocytosis is 

 not constant. The highest number they found was 15,000-34,000. 

 Schilling found a slight increase, 11,000 per cmm. 



DOURINE 



This disease affects equincs, mainly horses. Asses are less sus- 

 ceptible. Infection occurs naturally by coition. Dogs, rabbits, 

 rats and mice are easily infected by inoculation. 



Trypanosoma equiperdum closely resembles Tr. evansi and Tr. 

 brucci. Laveran and Mesnil state that the most important dif- 

 ference is in the absence of the protoplasmic granules such as are 

 present in Tr. brucei. Baldrey states that Tr. equiperdum is 

 smaller than Tr. evansi, the posterior extremity is not so long 

 and is less sharp, and the centrosome and nucleus are more 

 elongated. 



The parasites are found most easily in blood taken from the 



