Technical Abstract: Cryptosporidium parvum is a zoonotic pathogen transmissible from a variety of animals to humans and is a considerable public health concern. Dairy cattle have been identified in numerous reports as a major source of environmental contamination with this pathogen. However, virtually all reports have been based on microscopic examination of the organism in feces from cattle. The present review includes information based on molecular typing with the ssrRNA gene and subtyping with the GP60 gene that enables epidemiologists and others to trace the sources of Cryptosporidium –related outbreaks.