The efficacies of diloxanide furoate, beta -cyclodextrin and a cyclodextrin inclusion complex against Cryptosporidium parvum were evaluated in a suckling murine model. Efficacy was established by numbers of oocysts recovered from the intestinal tract of mice on day 7 postinfection. The level of infection in treated mice was significantly lower than in control mice and, surprisingly, the most efficacious treatment was beta -cyclodextrin, an excipient used in pharmaceutical technology.