1084 PATHOGENIC PROTOZOA 



about eight to ten microns from the same point. The posterior end 

 is blunt and the cytoplasm usually contains numerous basophile 

 granules; the undulating membrane is well developed and a 

 chromatin filament runs from the kinetonucleus to the tip of the 

 flagellum. The large kinetonucleus distinguishes this organism from 

 Trypanosoma equinum. 



PatJwlogical Anatomy. Aside from the emaciation, edema of the 

 belly wall, conjunctivitis and subconjunctival ecchymosis, there is 

 usually excessive fluid in the body cavities, an enlarged spleen, and, 

 what is more characteristic, small petechial spots on the capsule 

 of the spleen and in the cortex of the kidney and in the endo- and 

 pericardium and occasionally on the pleura! surfaces. 



Prophylaxis consists in the destruction of all infected animals; 

 the protection of wounds and ulcers in otherwise healthy animals 

 by dressings and, wherever possible, the use of fly screens about 

 the stables. 



Trypanosoma equiperdum (Do urine). This organism is the 

 cause of dourine, a disease of horses and donkeys, which is usually 

 transmitted by coitus, but may be carried by biting flies, stomoxys. 

 The organism was first described by Rouget in 1894; it resembles 

 brucei in many ways and produces a progressive, fatal disease of 

 great economic importance. Formerly it was present throughout 

 the greater part of Europe, but is now almost limited to the shores 

 of the Mediterranean. From time to time it has been introduced 

 into the United States and Canada by blooded French stallions and 

 has spread into parts of the Northwest. 



The clinical course may be divided into a stage of edema, lasting 

 about a month, during which there is a painless, soft swelling, 

 limited to the genitalia and the belly wall. This is followed by 

 the stage of eruption, during which plaques, or round edematous 

 areas, are found under the hide on the flanks and hind quarters, 

 and sometimes on thighs, shoulders and neck; this stage is short, 

 lasting about a week. It is followed by the third stage of paralysis 

 and anemia ; the animal loses flesh and strength, develops superficial 

 ulcers, conjunctivitis, keratitis, and ultimately paralysis, leading to 

 death in two to eighteen months. 



The trypanosome is found most readily in the serous exudate 

 from the ulcers, as it is infrequent in the peripheral circulation; 

 in this respect it resembles the treponema of lues. The organism 

 is about twenty-five microns in length and possesses a clear cyto- 



