Bovine Gastric and Intestinal Cryptosporidiosis

Present Situation

Abstract

This writer intends to provide information which will be useful or may be useful, next week in the practices of cattle practitioners. Comments on epidemiology, control and zoonotic potential of Cryptosporidium parvum (intestinal pathogen) were solicited for an oral presentation at the recent meeting of the American Association of Bovine Practitioners. But, from day-to-day bovine practice standpoint, there isn't much to say about this intestinal pathogen, despite the publication of about 1000 articles on cryptosporidiosis in the past 10 years. In fact, William Current and Lynn Garcia stated recently in a review article¹ (357 references) that, "Despite the large number of recent papers and the large number of laboratories throughout the world devoting significant effort in Cryptosporidium research, our present understanding of this protozoan parasite is very limited." Dubey, Speer and Fayer have published a complete reference book (1047 ref.) on cryptosporidiosis.² Many of the details of the following may be found among the references in these two sources.

Some preliminary informaton on the newly-discovered gastric pathogen of cattle, Cryptosporidium muris was added to the above-mentioned talk and has been added to this paper. Our understanding about this gastric cryptosporidial parasite is also limited because it simply hasn't been studied. Mention of the parasite here and results of preliminary investigations should stimulate some interest in promoting further study of this possibly significant chronic parasitism of the stomach of production animals.

Cryptosporidia are coccidial protozoan parasites related to the well-known eimerial coccidia; in other words, they are in the suborder, Eimeriorina. The original definitions were of the gastric and intestinal forms, C. muris and C. parvum, respectively, isolated from mice. Today the C. parvum designation is applied to isolates which cause enteritis in numerous mammalian species including humans. The C. muris organism differs from the enteric C, parvum not only in location (stomach) but in size and shape of oocyst. (See section on C. muris).