Abortion risk in progeny of cows after a Neospora caninum epidemic.
A study was done of the descendants of cows from 4 dairy herds in which there had been N. caninum abortion outbreaks. Precolostral antibodies to N. caninum were demonstrated in 34 of 50 (68%) F1 calves and in 14 of 17 (82%) F2 calves from cows that aborted during the outbreaks. In 214 F1 progeny, N. caninum seroprevalence was nearly 50%, and there was a significant association between serostatus of the offspring and serostatus of dams. These observations indicated that congenital infection was an important mode of transmission after abortion outbreaks in these herds. A total of 52 abortions was recorded in 293 pregnancies of F1 progeny cows (1 to 3 pregnancies per animal). It was found that seropositive F1 cows had a three-fold increased abortion risk compared with seronegative F1 cows. In 2 of 10 abortions in seronegative cows evidence for N. caninum infection was found, suggesting that a low level of postnatal infection may also have occurred. It is concluded that N. caninum-infected calves should not be used as replacement stock, to decrease the future risk of abortion in dairy herds.
Wouda
W
W
Department of Herd Health and Reproduction, Faculty of Veterinary Medicine, Utrecht, The Netherlands.
Moen
A R
AR
Schukken
Y H
YH
D000034:Abortion, Veterinary / Q000453:epidemiology* / Q000469:parasitology; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D003048:Coccidiosis / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*; D004196:Disease Outbreaks / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D007150:Immunohistochemistry; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary*; D008297:Male; D018688:Neospora / Q000276:immunology*; D009426:Netherlands / Q000453:epidemiology; D011247:Pregnancy; D012307:Risk Factors; D016036:Seroepidemiologic Studies
D000913:Antibodies, Protozoan