340 



SARCOCYSTIS, TOXOPLASMA AND RELATED PROTOZOA 



United States from Mexico. Gorlin et al. 

 (1959) found it in the lip of a burro of un- 

 specified origin in the United States. 



Morphology : Same as B. besnoiti. 

 According to Bennett (1933), the tropho- 

 zoites measure 10 by 4 /j,. 



B. 



Life Cycle : 

 besnoiti. 



Presumably same as 



Pathogenesis : According to Bennett 

 (1933), the horse-owning tribes in Southern 

 Kordofan know this disease quite well, can 

 differentiate it from mange and ringworm 

 and have given it a separate Arabic name. 

 It was said that one tribe which not many 

 years before had owned 600 to 800 horses, 

 now had less than 50 due to besnoitiosis. 

 On the other hand, the organism produces 

 no grossly recognizable disease in bur- 

 ros, according to Jones (1957). 



The disease as described by Bennett 

 (1933) in horses is a chronic one, running 

 a course of many months. Affected ani- 

 mals are weak and dejected, altho their 

 appetite is good. The skin is scurfy and 

 thickened, and contains many scabs and 

 whitish scars. The hair may be destroyed 

 by the lesions. The conjunctiva is a pecul- 

 iar brick red color, with a few petechiae. 

 The temperature is slightly elevated. 



The muscles in advanced cases are 

 pale brown and friable, but contain no 

 parasites. The Besnoitia cysts are 

 abundant in the skin and may also be found 

 in the mucous membrane covering the 

 larynx, nostrils, soft palate, etc. 



Diagnosis : Same as for B. besnoiti. 



Treatment: None known. 



BESNOITIA TARANDI 

 (HADWEN, 1922) NOV. COMB. 



Synonyms : Fibrocystis tarandi Had- 

 wen, 1922. 



Disease : Besnoitiosis, corn-meal 

 disease. 



Hosts : Reindeer, caribou. 



Location : The cysts occur in the 

 fibrous connective tissues, especially in 

 the periosteum and on the surface of the 

 tendons. 



Geographic Distribution : Alaska. 



Prevalence : Hadwen (1922) found this 

 parasite in a number of herds of reindeer 

 and in caribou in Alaska. 



Morphology : The cysts are spherical 

 and 100 to 450/1 in diameter with a mean 

 of 275 /i. They are composed of 3 layers, 

 of which the outermost is thick and fibrous, 

 with concentrically arranged fibers, the 

 middle layer is clear and hyaline, and the 

 inner layer forms a thin lining. The cysts 

 are not compartmented. The cyst contents 

 are dark brown. The trophozoites are 

 spindle shaped, with a central nucleus, 

 and measure 7 by 1.8|_l in alcohol-fixed 

 material. 



Life Cycle : Unknown. 



Pathogenesis : Reindeer owners call 

 besnoitiosis "corn-meal disease" because 

 of the granular nature of the lesions. The 

 cysts may be found in the periosteum of all 

 of the bones. When the periosteum is 

 stripped off, small pits corresponding to 

 their position are found in the bone itself. 

 They are also found on the surface of the 

 tendons, where they cause similar pits. 



Remarks: It is possible that the 

 same species of Besnoitia affects both 

 cattle and horses, and that B. ben>ietti is 

 a synonym of B. besnoiti. Until this is 

 shown to be the case by cross-transmis- 

 sion studies, however, it is considered 

 best to retain separate names for the 

 forms in cattle and equids. 



BESNOITIA JELLISONI 

 FRENKEL, 1955 



This species was described from the 

 deermouse, Peromyscus nianiculatiis, 

 in Idaho by Frenkel (1955). He trans- 

 mitted it by intraperitoneal or intravenous 



