Experimental reproduction of bovine fetal Neospora infection and death with a bovine Neospora isolate

• Published in: Journal of veterinary diagnostic investigation Vol. 6; no. 2; p. 207
• Main Authors: Barr, B.C, Rowe, J.D, Sverlow, K.W, BonDurant, R.H, Ardans, A.A, Oliver, M.N, Conrad, P.A
• Format: Journal Article
• Language: English
• Published: United States 01.04.1994
• Subjects: ABORTION; Abortion, Veterinary - parasitology; ABORTO; AGE; Animals; AVORTEMENT; Cattle; Cattle Diseases - parasitology; Cattle Diseases - pathology; Coccidia - isolation & purification; Coccidia - pathogenicity; Coccidiosis - parasitology; Coccidiosis - pathology; Coccidiosis - veterinary; COWS; DISEASE TRANSMISSION; EDAD; EXPERIMENTAL INFECTION; Female; FETAL AGE; FETAL DEATH; Fetal Death - parasitology; Fetal Death - pathology; Fetal Death - veterinary; Fetal Diseases - parasitology; Fetal Diseases - pathology; Fetal Diseases - veterinary; FETO; FETUS; FOETAL DEATH; FOETUS; INFECCION EXPERIMENTAL; INFECTION EXPERIMENTALE; MORT DU FOETUS; MUERTE FETAL; NEOSPORA; PATHOGENICITY; PODER PATOGENO; POUVOIR PATHOGENE; Pregnancy; TACHYZOITES; TRANSMISION DE ENFERMEDADES; TRANSMISSION DES MALADIES; TRANSPLACENTAL TRANSMISSION; VACA; VACHE
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/104063879400600212

Studies were conducted to determine the pathogenic potential of the recently isolated bovine Neospora protozoa (BPA-1) for the bovine fetus. Cows chosen for study had Neospora titers < 160 using an indirect immunofluorescent antibody (IFA) test. Four experimental groups were studied. In group 1, 2 fetuses were inoculated in utero at 118 days gestation with culture-derived Neospora tachyzoites. A pregnant control cow was housed in the same pen, observed daily and screened serologically for evidence of exposure to Neospora. In group 2, 2 cows were infected with Neospora tachyzoites at 138 or 161 days gestation, and 1 control cow was given uninfected cell culture suspension simultaneously at 154 days gestation. Groups 3 (85 days gestation) and 4 (120 days gestation) each consisted of 2 cows infected with Neospora tachyzoites and 1 control cow given uninfected material at the same stage of gestation. Dead fetuses were surgically removed from the infected cows in group 1 on postinfection day (PID) 17. The histopathology was compatible with protozoal fetal infection, and protozoa were identified by immunohistochemistry. Viable fetuses were removed surgically from cows in group 2 on PID 28-30. The histopathology was compatible with protozoal fetal infection, protozoa were identified by immunoperoxidase techniques, and Neospora tachyzoites were reisolated in vitro from tissues of the 2 infected fetuses. In groups 3 and 4, the control fetus and 1 infected fetus were removed surgically between PID 26 and PID 33. The remaining infected cows were observed until fetal death or abortion occurred.