The Morphology of Trichomonas ovis from the Cecum of Domestic Sheep

Abstract

Trichomonas ovis (Robertson, 1932) Morgan, 1946 was found in the ceca of 12 out of 16 domestic sheep in Illinois and Utah and was cultivated readily at 37 C in Diamond''s medium, CPLM medium and bovine cecal extract medium. It was studied by phase-contrast microscopy and after fixation with osmium tetroxide or Bouin''s or Hollande''s fixatives and staining with Giemsa, Heidenhain''s iron hematoxylin, or silver impregnation. It was piriform, 6 to 9 by 4 to 8 [mu] with a mean of 7 by 6 [mu], with an anterior nucleus, with a prominent pelta at the anterior end, with a slender, hyaline axostyle which protruded a mean of 5 [mu] beyond the body and gradually tapered to a point, without a chromatic ring at the point of exit of the axostyle, with 4 anterior flagella of unequal length averaging 14, 11, 9, and 7 [mu], respectively, with a prominent undulating membrane which extended from three-fourths to the full length of the body and usually had two of three undulations, with a posterior, free flagellum extending beyond the undulating membrane, with aprominent costa and several irregular rows of paracostal granules, with an avoid or club-shaped parabasal body averaging 2 by 1 [mu] and containing an intensely chromophilic body, and with a parabasal filament. This is the only species of enteric trichomonas of sheep or cattle which has been described in detail following study by modern techniques.