Studies on Sarcocystis and Other Cyst Forming Coccidia in the Sudan.

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Mohamed Warrag Omer, Omer
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A faecal and a sacocyst survey was conducted in animals in various parts of the Sudan to determine incidence of Sarcoystis and other cyst- forming coccidia. Dogs and cats were surveyed by faecal examination while camels, cattle, sheep and goats were inspected for sarcocysts. In the sarcocyst survey, a total of 50 camels, 45 cattle, 29 sheep, and 31 goats were examined. Oesophagus, heart skeletal muscles and diaphragm of each animal were inspected both macroscopically and microscopically by stained histological sections. No macroscopical sarcocyst was detected in any of the organs examined, but the rate of microscopic cysts was generally high in all animals. The highest rate of infection occurred in cattle (97.8%) followed by sheep (96.6%), goats (87.5%) and camels (82.0%). The predilection site of sarcocysts varied from one animal to another. The heart was the most affected in cattle while in sheep both the heart and the skeletal muscles were highly affected whereas the affected parts in goats were the skeletal muscles and diaphragm and the camels the oesophagus. In the faecal survey, samples from 100 stray mongrel dogs together with 17 police dogs (pure- bred German Shepherds) and 50 stray cats of different ages were examined for oocysts, sporocysts and other intestinal parasites using the floatation technique. Sarcocystis sporocysts were detected in more prevalence in dogs (11.0%) than in cats (2.0%). The canine species sporocysts measured 15.3 x 10.9 µm and the feline ones 13.0 x 8.6 µm. These sporocysts were ellipsoidal in shape with one side more convex than the other, smooth, coulerless or with a slightly yellowish tinge and contained four banana shaped sporozoites together with a coarse granular sporocyst residuum. Isospora oosysts were detected in 16 of the cats and in 4 of the dogs. Isospora canis occurred in four dogs, while five of the infected cats harboured mixed Isospora felis and I. rivolta; six had I. rivolta and the other five I. felis. Most of the Isospora-infected cats were young kittens indicating a higher susceptibility of young than older cats. The 17 police dogs were free of internal parasites and no Toxoplasma-like oocysts could be detected in any of the 50 cats examined. Life cycle studies were conducted with camel Sarcocystis in order to determine the final host and the possible identity of this parasite. Portions of camel tissues were digested to confirm the presence of bradyzoites and positive tissues were fed to six dogs and four cats that were that were reared in the laboratory on bread and milk only. The dogs and not the cats proved to be the final hosts for this Sporocsytis species. On this basis, as well as morphology of sarcocysts, oosysts and sporocysts, the prepatent and patent periods in the final host, Sarcocystis species found in the Sudanese camels is named Sarcocystis camelocanis sp. n. Some of the dogs were fed raw camel meat, shed unsporulated Hommondia heydorni oocysts indicating that the camel is an intermediate host of this parasite.
on Sarcocystis and Other Cyst Forming Coccidia in the Sudan