Experimental cryptosporidiosis in calves

Wee, Sung-hwan; Lee, Chung-gil; Kang, Yung-bai; Joo, Hoo-don; Joo, Yi-seok; Park, Yong-ho; Choi, Sang-ho

Korean Journal of Veterinary Research 1995;35(1):107-113.

Sung-hwan Wee¹, Chung-gil Lee², Yung-bai Kang¹, Hoo-don Joo¹, Yi-seok Joo¹, Yong-ho Park¹, Sang-ho Choi¹

¹National Veterinary Research Institute, RDA
²College of Veterinary Medicine, Chonnam National University

송아지의 실험적 크립토스포리디움증

위성환¹, 이정길², 강영배¹, 주후돈¹, 주이석¹, 박용호¹, 최상호¹

¹수의과학연구소
²전남대학교 수의과대학

Abstract

Four Holstein calves 7-day-old were infected with C parvum oocysts for parasitological and pathological investigations of bovine cryptosporidiosis. Of those calf 1 was orally administered with $7{ imes}10^6$ oocysts of C parvum isolated from a Korean mouse (VRI-CN91), and calf 2 with same number of C parvum oocysts provided by Washington State University(WSU). The rest (calf 3 and 4) were orally administered with $1{ imes}10^8$ oocysts of VRI-CN91 strain. Calf 1 commenced to discharge oocysts in feces at days 6 post inoculation(PI), and it reached a peak $1.4{ imes}10^7$ oocysts per gram of feces(OPG) on day 8 PI. Calf 2 commenced to discharge oocysts in feces at day 4 PI, and it reached a peak $3.75{ imes}10^6$ OPG on day 7 PI. Calf 3 and 4 commenced to discharge oocysts in feces at day 3 and day 4 PI, and it reached a peak on day 7 PI (calf 3, $7.8{ imes}10^6$ OPG; calf 4, $1.7{ imes}10^6$ OPG). Clinically, the calves began to show mucoid-watery diarrhea at day 3 to 5 PI, and the sign lasted 5 to 7 days. Calf 2 died on day 9 PI with a severe dehydration. On necropsy the intestine was found to be congested and hemorrhagic. Protozoan oocysts were observed mainly in the ileum and occasionally in jejunum. The results in the present study indicate that the Korean isolate was pathogenic in calves.

Key Words: cryptosporidiosis, Cryptosporidium parvum, diarrhea, calves