Ingestion of Neospora caninum tissue cysts by Mustela species

Dogs are a definitive host of Neospora caninum, a protozoal parasite that causes abortion in cattle. Mustelids were tested to determine if they could also be definitive hosts. The procedures used were the same as those previously used to test dogs. Ermine (Mustela erminea), weasels (Mustela frenata) and ferrets (Mustela putorius) were fed N. caninum-infected mice. Neospora caninum oocysts were not observed. Mustelid faeces were fed to mice. The mice did not seroconvert and N. caninum was not detected in murine brains using tissue culture and PCR. The hypothesis that Mustela spp. are definitive hosts of N. caninum is not supported.