434 



VETERINARY BACTERIOLOGY 



Two forms are described: long slender cells, 25 to 35 {i in length 

 by about 1.5 ft in width, with narrow, undulating membrane and 

 fairly long flagellum, and short broad forms, 14 to 20 by 3 to 4 [i, 

 with no free flagellum and a wide, undulating membrane. 



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Fig. 190. Trypanosoma pecaudi (Laveran). 



Pathogenesis. Character of Disease and Lesions. In the horse 

 the disease is characterized by repeated attacks of a severe fever, 

 swellings in various parts of the body, injection of the conjunctiva, 

 and a considerable degree of emaciation. 



Trypanosoma cazalboui 



Disease Produced. Souma or soumaya in cattle, sheep, horses, 

 and mules. 



Distribution. Africa, from the French Sudan, French Congo, 

 Upper Nile. 



Morphology. The organism, including its free flagellum, is 

 about 21 by 1.5 {i. The oval nucleus is centrally located. The 

 undulating membrane is poorly developed and is little folded. The 

 terminal portion of the flagellum is free. There are no marked 

 characters differentiating the organism from Tr. evansi. 



Pathogenesis. Experimental Evidence. Laboratory animals, 

 particularly the rodents, seem to be relatively immune. The 

 infection may be readily transmitted to horses and cattle and the 

 smaller ruminants. Cross-inoculation experiments have shown 

 the disease to be distinct from surra. 



Character of Disease. It attacks cattle generally. The disease 

 leads to a progressive emaciation, the skin is harsh, and there is 



