Renal coccidiosis with cystic tubular dilatation in four bats

Abstract

Renal coccidiosis was diagnosed in four bats of different species (Pipistrellus pipistrellus, Myotis mystacinus, M. nattereri, and Nyctalus noctula). Multiple white and partly indented foci up to 2 mm in diameter were visible on the renal surface. Histologically, the foci appeared as cystic dilated tubules with proliferated epithelium. Asexual and sexual coccidian stages were seen in the epithelial cells, and the extremely distended tubular lumina were filled with schizonts, free zoites, microgamonts, macrogamonts, and unsporulated oocysts. Because the majority of the renal tissue appeared uninvolved in the disease process at the gross and histologic levels and there was no evidence for uremia in other organs, renal function was probably not impaired. Precise classification of the coccidia was impossible because no sporulated oocysts were available. The parasite morphology and the hitherto unreported cystic dilatation of infected tubules containing all developmental stages differ from renal coccidioses reported previously and therefore suggest an undescribed coccidian species.