Lindsay D S, Rippey N S, Powe T A, Sartin E A, Dubey J P, Blagburn B L
Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849, USA.
Am J Vet Res. 1995 Sep;56(9):1176-80.
Neospora caninum-induced abortion is a major production problem in the dairy cattle industry in the United States and worldwide. Abortions attributable to naturally acquired N caninum infection also have been observed in pygmy goats. We studied experimentally induced infections with N caninum in pregnant pygmy does to determine whether abortions attributable to N caninum infection would occur after inoculation. Seven pregnant pygmy does (1 control doe and 6 inoculated with N caninum) were studied. The control doe remained clinically normal throughout the study and delivered 2 healthy kids. Abortion, fetal death, and stillbirths were observed in some pregnant does inoculated with N caninum. Two pregnant pygmy does inoculated with N caninum early in gestation (day 51) had fetuses that died and were aborted, or died and were reabsorbed. Neospora caninum tachyzoites and lesions were observed in the brain, spinal cord, and heart of aborted fetuses; parasites also were isolated from the placenta. Four additional pregnant pygmy does (2 inoculated at mid-gestation [day 85], and 2 at late gestation [day 127]) did not abort after inoculation. However, 1 doe inoculated during mid-gestation delivered a stillborn fetus that had died about 1 week prior to parturition. This kid was congenitally infected with N caninum. Neospora caninum was isolated from the placentas of all inoculated does examined. Neonatal neosporosis was not observed in live-born kids, nor were stages of N caninum isolated from any live-born kid. Does did not undergo abortion or have congenitally infected kids when they were rebred and evaluated for neosporosis.
犬新孢子虫引起的流产是美国及全球奶牛业的一个主要生产问题。在侏儒山羊中也观察到了自然感染犬新孢子虫导致的流产。我们对怀孕的侏儒母羊进行了犬新孢子虫的实验性感染研究，以确定接种后是否会发生犬新孢子虫感染所致的流产。研究了7只怀孕的侏儒母羊（1只对照母羊和6只接种犬新孢子虫的母羊）。对照母羊在整个研究过程中临床正常，产下2只健康的小羊。在一些接种犬新孢子虫的怀孕母羊中观察到了流产、胎儿死亡和死产。2只在妊娠早期（第51天）接种犬新孢子虫的怀孕侏儒母羊的胎儿死亡并流产，或死亡并被吸收。在流产胎儿的脑、脊髓和心脏中观察到犬新孢子虫速殖子和病变；寄生虫也从胎盘中分离出来。另外4只怀孕的侏儒母羊（2只在妊娠中期[第85天]接种，2只在妊娠晚期[第127天]接种）接种后未流产。然而，1只在妊娠中期接种的母羊产下了1只死产胎儿，该胎儿在分娩前约1周死亡。这只小羊先天性感染了犬新孢子虫。从所有检查的接种母羊的胎盘中分离出了犬新孢子虫。在出生存活的小羊中未观察到新生儿新孢子虫病，也未从任何出生存活的小羊中分离出犬新孢子虫的各阶段虫体。母羊再次配种并评估新孢子虫病时，未发生流产或产下先天性感染的小羊。
