Description Neosporosis has been recognized in dogs, cattle, sheep, goats, deer, horses, and experimentally rodents, pigs, monkeys, and cats. It is a major cause of abortion in dairy cattle.
The protozoan NEOSPORA CANINUM is a cause of abortion in cattle and congenital infection in calves. Aborted tissue typically has multifocal gliosis and malacia in central nervous tissue, myocardial necrosis, mononuclear myocarditis and multifocal placentitis. Bovine abortions appear to be most common after 90 days of gestation with a peak at 5-7 months. N. CANINUM has also been associated with abortion in sheep and goats but natural infection is uncommon.
N caninum is a major cause of abortion in many countries. Calves may be aborted; stillborn; born underweight, weak, or paralyzed; or they may become paralyzed within 4 wk of birth. Nonsuppurative encephalitis is the main lesion in aborted fetal tissues. Abortion can occur throughout gestation, and some cows may abort again; dams of these calves are clinically normal.