Neospora caninum-like Protozoon Associated with Fatal Myelitis in Newborn Calves

Abstract

Neospora caninum-like organisms were found in histologic sections of sinal cord of 4 paralyzed calves as reported by Parish et al. (1987). Tachyzoites divided by endodyogeny. Tissue cysts were up to 62 .mu.m wide and the cyst wall was up to 2.5 .mu.m thick. The organism in calves was structurally distinct from Toxoplasma gondii and Sarcocystis species and reacted positively with anti-N. caninum serum in an immunoperoxidase test.