Caleffo, Tatiane, et al. “Occurrence of Lawsonia Intracellularis in Horses Raised in Three Regions of the State of Paraná, Brazil”. Semina: Ciências Agrárias, vol. 42, no. 5, July 2021, pp. 2867-76, doi:10.5433/1679-0359.2021v42n5p2867.