2023 Volume 76 Issue 2 Pages e18-e27
Five calves died at two farms in Ishikawa prefecture, Japan, in 2020. Pathological examinations revealed that these calves may have been infected with Cryptosporidium spp. PCR of 18S rRNA genes and a multiplex PCR of actin genes identified two genotypes of Cryptosporidium parvum, type 1 and type 2, which included 3 bp deletions and 2 bp substitutions, in all calves. This is the first report of mixed infections with multiple genotypes of Cryptosporidium. C. bovis and C. ryanae were also detected in other calves reared at the same farms. Environmental examinations of the farms by PCR revealed that Cryptosporidium spp. were present only in the rice husks that were used as bedding litter. The rate of animals with diarrhea was reduced by treating the areas in which the calves were reared with boiling water and milk of lime. However, the infections could not be completely eliminated.
