The microsporidian parasite Enterocytozoon hepatopenaei (EHP ) has spread from its initial geographical origin, Thailand, to other major shrimp producing countries around the world and continues to impact the production of penaeid shrimp and other commercially important crustaceans. As the economic losses due to EHP spread continues to accrue, many aquafeed and other aquaculture companies from around the world are working on to develop preventative and therapeutic measures to contain the disease . Over the past few years, numerous EHP bioassays have been conducted in the Aquaculture Pathology Laboratory at the University of Arizona to develop therapeutics, preventative diets, and EHP-resistant Peneus vannamei lines. Collectively, these experiments have provided valuable insights into: (a) the challenges associated with early-stage EHP infections, ( b) how EHP infections spread with low prevalence , (c) short-term effect of EHP on growth of shrimp, (d) observation time needed to gain meaningful data on the reduction in parasite load following a therapeutic treatment, as measured by PCR-based diagnosis and histopathology (e) population size, number of tanks, and the size of tanks to be considered before designing an experimental bioassay for therapeutic development, and screening of genetic lines for EHP resistance.