<i>Neospora</i>-Like Protozoal Infections Associated with Abortion in Goats

Abstract

Neospora caninum was first identified and described in 1988 from a litter of puppies with encephalomyelitis. Since this first report, naturally occurring neonatal or fetal infections caused by Neospora-like protozoa have been described in cattle, sheep, and horses. Abortion or neonatal infection in cattle by this Neospora-like protozoa have been reported throughout the United States and in several other countries. Additionally, experimental infections have been produced in cats, rats, and mice. We report on 2 unrelated cases of abortion associated with a Neospora-like protozoan in pygmy goats. The first fetus and placenta (Fetus A), from a 2-year-old doe, were submitted in November 1989 from a small farm east of Sacramento, California. The doe had an uneventful pregnancy the previous year. The owner reported that abortions had occurred in 3 other does during the previous 2 years. These fetuses had been necropsied, but the etiology in each case was undetermined. No additional history on the flock was available. The fetus was 130 days gestational age and had a 24-cm crown-rump length. It was autolyzed, with blood staining of tissues and large amounts of deep red serous fluid in the body cavities. There were no significant gross pathologic findings. The placenta was very edematous. The second fetus and placenta (Fetus B) were submitted in March 1991 from a farm in the Sacramento Valley north of Sacramento, California. There was no history on this flock. The fetus had a 14-cm crown-rump length with no body hair. It was partially mummified with a small amount of fetal fluid in the thorax. There were no significant gross pathologic findings. Bacterial cultures of placenta, lung, liver, and abomasal fluid, darkfield examination of abomasal fluid, Chlamydial and viral cultures of pooled tissues, fluorescent antibody tests of kidney and placental impression smears for Leptospira spp. and Chlamydia psittaci, respectively, were performed as previously described and were all negative for both fetuses. Fluorescent antibody tests for border disease using frozen sections of liver and lung were negative in both fetuses. The total immunoglobulin G level in fluid from Fetus A was 2,720 mg/dl and in Fetus B was > 100 mg/dl. There was no antibody to Brucella ovis (enzyme-linked immunosorbent assay), bluetongue virus (agar-gel immunodiffusion), Leptospira spp. (microagglutination test), or Toxoplasma gondii (latex agglutination at a 1:16 dilution) in either fetus. Nitrate