Serum, top coating, was first separated, and then, using a pipette, the buffy coating was collected. 2.2. of 26 out of 127 (20.47%) cattle. Even though infection was more common in females and in five-year-old cattle by serology and molecular methods, yet there was no statistically significant difference between age, sex, and illness in both molecular and serological methods ( 0.05). Conclusion Findings of the current study indicate a high rate of illness in cattle of Boyer-Ahmad region in the southwest of Iran. This problem should be further investigated and the prevention and control of this parasite in livestock, due to the high monetary burden of this parasite in the livestock market, should be considered. 1. Intro Neosporosis is an important disease in dogs and cattle with a global prevalence . This disease is known as one of the main causes of abortion in cattle and neuromuscular paralysis in dogs . The causative agent of neosporosis is an obligate intracellular protozoan and a member of the phylum Apicomplexa. Probably one of the Leuprolide Acetate most important genus and varieties of which is definitely . In cattle, the two main routes of illness are vertical transmission from mother to fetus, as well as transmission through ingestion of contaminated water or forage with oocysts excreted in puppy feces . Studies in different areas of the world show that a high percentage of aborted fetuses in cattle is due to illness with this parasite [4C6]. causes miscarriage in cattle, and most miscarriages happen in the second trimester of pregnancy. The embryos are often autolyzed and may become deceased or mummified in the uterus and even reabsorbed. Abortions happen throughout the year, Leuprolide Acetate both in the first and in subsequent deliveries . Sometimes fetuses Leuprolide Acetate are given birth to prematurely or seemingly healthy, without clinical indicators . Neosporosis is usually a common contamination in livestock in Iran. According to a recent meta-analysis, the overall seroprevalence of bovine neosporosis in Iran ranges between 3.8 and 76.2% . In a study by Sadrebazzaz et al. in Mashhad, East of Iran, 15.19% of cattle were found to be infected with infection was detected in 36% of the studied cattle . In Ranjbar et al.’s study on aborted dairy cattle in Garmsar city, southeast of Tehran, 38.5% of analyzed animals were positive for and there was a significant association between the prevalence of infection and the frequency of abortion in the analyzed cattle . Rafati and Jaafarian’s study on 100 aborted bovine embryos in Shahrekord in the southwestern a part of Iran revealed that 11% of the samples are infected with parasite, by molecular method . Ansari-Lari et al. reported a seroprevalence of Leuprolide Acetate 30% for contamination in cattle in Shiraz, south of Iran . A serological study of bovine neosporosis by Sengupta et al. in India revealed that 10% of the samples were infected with and that there was a significant association between abortion and serum contamination with . A study in Argentina by Fort et al. on 4334 bovine serum showed that 302 (6.9%) of the cases were serologically positive for infection . Due to the high economic importance of this disease and also the presence of very different climates in different parts of Iran and the lack of sufficient information about this disease Mmp8 in livestock in different parts of the country, the present study is usually aimed at evaluating the status of contamination in cattle in Boyer-Ahmad County in Kohgiluyeh and Boyer-Ahmad province, southwest of Iran, by molecular and serological methods. 2. Materials and Methods 2.1. Sample Collecting In this cross-sectional study, 150 blood samples were.