We investigated the occurrence of Cryptosporidium oocysts shedding by domestic cats in an urban setting. The calculation of minimum sample size was based on an estimated prevalence of 10%, 5% absolute sampling error and a 5% significance level, resulting in 138 cats. A total of 612 owners of 2,290 cats had to be contacted for achieving the minimal sample size. In the end, only 55 owners accepted to participate ...