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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #66848
Title: FIELD TESTING OF PROPHYLACTIC MEASURES AGAINST CRYPTOSPORIDIUM PARVUM INFECTION IN CALVES IN A CALIFORNIA DAIRY HERD

Author
item Harp, James
item JARDON, PHILLIP - UNIV. OF CALIF.-DAVIS
item ATWILL, E - UNIV. OF CALIF.-DAVIS
item ZYLSTRA, MIKE - UNIV. OF CALIF.-DAVIS
item CHECEL, STEPHANIE - UNIV. OF CALIF.-DAVIS
item Goff, Jesse
item DE SIMONE, CLAUDIO - UNIV. DE L'AQUILA, ITALY

Submitted to: American Journal of Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cryptosporidium parvum is an intestinal parasite that causes diarrhea in young calves. A nationwide survey found that one-half of the calves surveyed were infected with Cryptosporidium, and the disease has been estimated to cost producers in excess of $100 million per year. This parasite can also contaminate water supplies and cause disease in humans. There are presently no drugs to control this parasite and no effective means of preventing infection. We tested two potential treatments for Cryptosporidium in calves on a large dairy farm in California. One group of calves was vaccinated with an experimental vaccine, a second group received doses of bacteria similar to those found in yoghurt, and a third group received no treatment. The incidence of Cryptosporidium infection was high in all three groups, indicating heavy contamination of this farm with the parasite. Fewer calves in the group receiving bacteria treatment were infected compared with the other groups. Further work is necessary to determine the significance of this effect. Development of effective means of preventing Cryptosporidium infection will reduce economic losses to producers, as well as reducing contamination of the environment with the parasite.

Technical Abstract: Cryptosporidium parvum is a major cause of neonatal diarrhea in dairy calves. Infected calves may also be a source of infection for humans by contamination of the environment with the parasite. There are no effective prophylactic measures against this parasite in humans or animals. We evaluated two methods to control infection in a California dairy herd with a high incidence of C. parvum in neonatal calves. One group of calves received an oral vaccine against C. parvum previously shown to reduce diarrhea and oocyst shedding in experimentally infected calves. A second group of calves was dosed with a mixture of lactic acid-producing bacteria known to have beneficial effects in other enteric infections. A third group served as untreated controls. The overall rate of infection with C. parvum, determined by fecal shedding of oocysts, was 92% during the period of study. Ninety-four percent of control calves were infected, 95% of calves in the vaccine group were infected, and 86% of calves in the lactic acid-producing bacteria group were infected. The course of diarrhea and oocyst shedding during the study was similar for all three groups. Thus, neither of the treatments had any significant effect in this study.