The aim of the present study was recording the type and rate bacteria causing abortion in Arabian horse. Study the presence of leptopira in stallion`s semen by isolation serodiagnosis and molecular identification in semen samples.
A total number of 171 samples collected, Samples were cultured for isolation of bacteria as well as leptospira species. 53 different isolates (40.2%) were obtained from different samples (132), 5.3% of samples showed mixed infection (2 from uterine washes and 5 from fetal samples).. The rate of different isolates in different samples were recorded, where S.equi subsp. zooepidemicus and P.aeruginosa showed the highest rate of isolation (4.5%) followed by klebsiella pneumonia subsp pneumonia and Streptococcus equi subsp. equi. negative isolates from the equine uterus.  Burkholderia cepacia complex (BCC) and S.equi subsp. equi were isolated in a rate of 3.8%. Rhodococcus equi and S. enterica subsp. Arizonae were isolated in a rate of 3%.. Listeria monocytogenes (L.monocytogenes) was isolated in a rate of 2.3%; Arcanobacterium haemolyticum (A.haemolyticum) and Staphylococcus aureus (S.aureus) were isolated in a rate of 1.5%. This was the first report on isolation of A. haemolyticum from aborted mares. Enterobacter aerogenes (E.aerogenes); Hafnia alvei (H.alvei) S. enterica subsp. enterica Typhimurium (S.Typhimurium) and Staphylococcus haemolyticus (S. haemolyticus) were isolated in a lowest rate 0.8%.