Veterinary Abortion Surveillance as an Epidemiological Tool: A Seven-Year Study in South Bačka and Srem, Serbia (2019–2026)

Abortions represent one of the most important reproductive disorders in livestock production, causing substantial economic losses and providing valuable epidemiological information on circulating infectious diseases. This study analyzed reported abortion cases in domestic animals from the South Bačka and Srem districts of Serbia during the period 2019–2026.

A total of 1,262 abortion cases were investigated, including 255 in cattle, 972 in pigs, 33 in sheep, and 2 in mares. Maternal sera were examined serologically for major viral, bacterial and parasitic abortifacient pathogens, while aborted fetuses were tested using PCR/RT-PCR, qPCR/RT-qPCR and bacterial culture when appropriate (Listeria sp.).

In cattle abortion cases, C. burnetii and Leptospira spp. were the most prevalent pathogens detected (7.06%), followed by Listeria spp. (3.92%), N. caninum (3.53%) and BVDV (3.14%). T. gondii (1.18%), and B. abortus, C. abortus and BHV1 (0.39%) were less prevalent. Highest seroprevalence was detected for BVDV (66.27%), BHV1 (28.63%) and C. burnetii (18.82%) followed by N. caninum (12.16%).

In pigs, Leptospira spp. was the most commonly detected pathogen (6.53%), followed by T. gondii (2.61%), PRRSV (2.65%) and PCV2 (2.26%). B. suis was found in 0.93% cases. Interestingly, PPV was detected very rarely (0.73%), although the seroprevalence was the highest (97.84%; 951/972). Seroprevalence was also high for PRRSV (62.65%) and PrV (36.73%), while it remained below 5% for all other tested pathogens.

Among sheep abortions, C. burnetii was the most prevalent pathogen (9.09%), followed by N. caninum and T. gondii (6.06% each). No abortion cases were recorded in goats during the study period. Of the two equine abortion cases, one was positive for EHV1 and the other for EAV.

The obtained results could be used, as already implemented in Serbia, to develop more detailed herd- or region-based surveillance programs and to design targeted, small-scale (hotspot-based) pathogen prevention and control strategies.