Pathogenicity of Leucocytozoon caulleryi for specific pathogen-free layinghens

The pathogenicity of Leucocytozoon caulleryi against specific-patho.-en-fre e laying hens was investigated. Many large schizonts (second-generation sch izonts) of L. caulleryi were seen in the ovary and oviducts of chickens. Ed ema and pressure atrophy of the adjacent tissues were associated with these schizonts. The eggshell-secreting portion of the uterus exhibited the most severe damage in the oviduct. This experiment reconfirms that L. caulleryi may stop egg production in laying hens, presumably as a result of damage t o ovaries and oviducts.