Infectivity of Cryptosporidium muris directly isolated from the murine stomach for various laboratory animals.

Oocysts of Cryptosporidium muris, directly isolated from the stomach of experimentally infected laboratory mice were orally inoculated into rats, gerbils, guinea pigs, dogs, and rabbits. Weaned rats developed patent C. muris infection as evidenced by the endogenous stages in gastric glands and oocyst shedding 10-17 days later. No signs of clinical illness or macroscopic findings were detected in mice and rats. Laboratory raised suckling rabbits, guinea pigs, gerbils and dogs fed C. muris rarely developed patent infections and they were considered not a true host for C. muris.