Serological Evidence of Selected Abortifacients in a Dairy Herd with History of Abortion

Abortion is common among dairy herds in Pakistan. However, except for Brucella abortus, little is known about other prevalent abortifacients. Therefore, a sero-epidemiological study was conducted in a dairy herd with a history of abortion located in Lahore, Pakistan. Blood samples (3–5 mL) were taken from each animal (cows, n = 43; buffaloes, n = 47) in the herd. Seropositivity to infectious bovine rhinotracheitis (IBR), B. abortus, blue tongue virus (BTV), bovine viral diarrhea virus (BVDV) and Toxoplasma gondii was determined using commercially available kits. Among cows and buffaloes, seropositivity was most frequent for IBR (69.8 and 70.3%, P>0.05), followed by B. abortus (32.6 and 42.6%, P>0.05), BVDV (9.3 and 6.4%, P>0.05) and BTV (4.7 and 6.4%, P>0.05), whereas, all the animals were seronegative to T. gondii. With respect to age, there was a significant difference (P<0.05) in seropositivity to B. abortus, BTV, and to multiple infectious agents in buffaloes. Additionally, a history of prior abortion was found to be significantly associated with current abortion in buffaloes and cows (P<0.001). While several significant associations between seropositivity to various agents and abortion were initially found, further analyses showed no significant associations in cows or buffaloes. The study concludes that seropositivity to the studied infectious agents was not significantly associated with abortion when accounting for other covariates, while prior abortion was found to be significantly associated with current abortion in both cows and buffaloes. However, owing to the small preliminary nature of the study, small sample size, and small number of abortion events, further studies are needed to ascertain the validity of these results.