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Eimeria Ellipsoidalis nov. spec., a New Coccidium of Cattle

1929; American Society of Parasitologists; Volume: 15; Issue: 3 Linguagem: Inglês

10.2307/3271674

1937-2345

Elery R. Becker, William W. Frye,

Parasitic Infections and Diagnostics

In a previous paper we reported the results of a survey of the protozoan population of the feces of calves. Up to the present writing forty calves have been examined. Three of these animals were found to be infected with coccidia of the genus Eimeria. The oocysts of two calves were so distinctly different from those of the third, as to suggest that we were dealing with two distinct species. The idea that there may be more than one species of coccidia parasitic in the cow is not new since Reichenow, Smith and Graybill, Yakimoff and Galouzo and others have previously submitted evidence in support of it. The history of bovine coccidiosis begins with Ziirn (1878) who wrote an account of his observations upon the intestine of a calf which had died of acute intestinal inflammation caused by coccidia; or, to quote directly, durch Gregarinen hervorgerufene Enteritis in optima forma. No description of the parasite is given. He does mention, however, that rabbits were not kept with the calves, and thus implies that the rabbit coccidium was not responsible for the infection in the calf. Rivolta (1878) gave the name Cytospermium ziirni to the gregarine which Zurn had observed. He states that Ziirn did not give a definite description of the parasite, and he gives none beyond saying that it seems identical to the species described by Eimer in rats or to the psorosperm of the rabbit. Although neither Ziim nor Rivolta gave a definite description of the parasite, both had in mind the causative agent of a particular form of enteritis of cattle. Beginning with Guillebeau (1893) a number of workers reported two types of oocysts of Eimeria from cattle. (Vide Yakimoff and Galouzo, 1927, for adequate historical account). Smith and Graybill (1918) designated the two types which they observed in calves in New Jersey as two species. The one species was usually elliptical, occasionally ovoid or circular. Most of the individuals measured would fall within a range of length from 13.1 to 28.7,u and of width from 12.3 to 20.5,; average length, 18.6,u; average width, 14.8,/. There was no residual body within either the cyst or the spore after development. The second species was distinctly ovoid and brownish or colorless. There was no residual body within the cyst, but one was present in each spore. Size of oocysts, 25.8 to 41.8,u by 16.4 to 24.6,u; average, 29.9 by 19.9,u.