Neosporosis as a cause of abortion in dairy cattle in Rio Grande do Sul, southern Brazil.
Forty-six aborted bovine fetuses submitted to the Faculty of Veterinary, Department of Clinical Pathology, Universidade Federal do Rio Grande do Sul, were examined histopathologically. Non-suppurative inflammation was observed mainly in the brain and heart of 22 fetuses. Brain lesions consisted primarily of mononuclear inflammatory cell infiltrates with occasional foci of necrosis. Protozoa that reacted with Neospora caninum antisera were seen in 18 of the 22 (81.8%) brain specimens from fetuses with encephalitis. Blood samples collected from 223 Holstein cows on five dairy herds were tested for N. caninum antibodies by an immunofluorescent antibody technique. These samples were obtained from aborting cattle and normally calving cattle (control group). Overall, 11.2% of cows sampled had N. caninum antibodies at a dilution of 1:200. Seroprevalence was higher (P = 0.0053) in aborting (23.3%) than in non-aborting cows (8.3%). Association between seropositivity to N. caninum and abortion was found, with seropositive cows being 3.3 times more likely to abort than seronegative cows (OR = 3.33; 95% CI: 1.38, 8.062). Additionally, N. caninum antibodies were detected in sera from seven cows that had aborted fetuses with lesions suggestive of protozoal infection. These results suggest that N. caninum is an important cause of abortion in dairy cattle in Rio Grande do Sul State, Brazil.
Corbellini
L G
LG
Faculdade de Medicina Veterinária, Departamento de Patologia Clínica Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, CEP 91540-000, Porto Alegre, Rio Grande do Sul, Brazil.
Driemeier
D
D
Cruz
C F E
CF
Gondim
L F P
LF
Wald
V
V
D000034:Abortion, Veterinary / Q000453:epidemiology / Q000469:parasitology*; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001921:Brain / Q000469:parasitology / Q000473:pathology; D001938:Brazil / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000453:epidemiology / Q000469:parasitology*; D003048:Coccidiosis / Q000097:blood / Q000453:epidemiology / Q000662:veterinary*; D005260:Female; D009206:Myocardium / Q000473:pathology; D018688:Neospora / Q000276:immunology / Q000302:isolation & purification; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000097:blood / Q000453:epidemiology / Q000662:veterinary*; D016036:Seroepidemiologic Studies
D000913:Antibodies, Protozoan