Abstract
102 A. terrestris (all juveniles) were caught between July 1992 and July 1993 from an area near the French village of Le Souillot, dissected and examined for coccidian tissue cysts. Five of the animals were found to have tissue cysts in their brains. Although histological sections of the 5 infected brains all revealed round cysts, each measuring <150 micro m in diameter, 2 of the brains had cysts that were morphologically similar to those of T. gondii, with crescent-shaped zoites. The cysts in the other three brains had spherical zoites, each with a central nucleus. Immunoperoxidase labelling confirmed the two brains had T. gondii cysts (2%). The cysts in the other 3 infected brains, which showed no reaction with the anti-Toxoplasma or anti-Neospora sera, were assumed to be young cysts of Frenkelia.