BACKGROUND: Over the recent years, Neospora caninum has been one of the most important causes of abortion in dairy cattle. OBJECTIVES: We conducted the present study in order to investigate the seroprevalence of N. caninum in dairy cattle in Semnan province and its effect on abortion. METHODS: 237 blood samples were obtained from various Semnan dairy farms and 104 bulk dairy samples from four milk collection centers in Semnan, Garmsar, Damghan, and Shahrood were tested for sera and milk utilizing ELISA (Svanova Biotech AB) test kits. RESULTS: The results revealed that 87.27 % of bovine serum was positive. The percentage of opacity density (OD) of positive sample (PP) ranged from 72.17 to 137.3 (114.21±24.65). In addition, the average rate of milk seroprevalence to the parasite was 95.23 % in Semnan province. CONCLUSIONS: The frequency of Neospora caninum infection in blood and milk was high in Semnan, yet no significant relationships were observed with abortion (p < /em>>0.05).

BACKGROUND: Toxoplasma gondii is a zoonotic obligate intracellular protozoan parasite that infects all warm-blooded animals as well as human worldwide. Human is infected with Toxoplasma parasites by eating half-cooked meat of livestock or oocyte. OBJECTIVES: The purpose of this study was to determine the presence of Toxoplasma in aborted fetuses of sheep using the serological method in North Khorasan province. METHODS: In this study, from 2015 to 2017, 133 samples of the thoracic fluid in aborted fetuses of sheep from different cities of North Khorasan Province were collected and sent to the central laboratory of Bojnourd. For each sample, a questionnaire was prepared for gathering information such as age and city, and then, the antibody level was determined in each sample by ELISA method. RESULTS: In this study, the age of 133 aborted fetuses of sheep was more than 120 days. Also, of the 133 aborted fetuses of sheep, 14 samples (10.53%) were infected with Toxoplasma parasites. The highest and lowest rate of Toxoplasma infection was observed in 2016 and 2017, respectively. Also, the most infection was found in Shirvan and Faroj cities. Results of chi-square test showed that there was a significant difference between year and abortion in sheep due to infection with Toxoplasma parasite (P<0.05). There was not significant difference between the frequency of this parasite infection and aborted fetuses in different areas (P> 0.05). CONCLUSIONS: The results of this study indicate that Toxoplasma gondii infection is one of the causes of abortion of sheep in North Khorasan province, and sheep is one of important sources of meat and dairy products in this area, Therefore, observance of public health tips and the complete cooking of meat and boiling milk is emphasized.

BACKGROUND: Neospora caninum is one of the most important pathogenic protozoan parasites causing bovine abortion around the world. Objectives: The aim of this study was to detect the presence of Neospora caninum in the brain, cerebellum and medulla oblongata of aborted fetuses in cattle in Arak by means of molecular method. Methods: 38 samples of brain, cerebellum and medulla oblongata from aborted fetuses in dairy cattle of Arak were tested for the presence of Neospora with nested-PCR. Results: Survey findings indicated the presence of DNA in 26.3 % of aborted fetal brains. In the cerebellum and medulla oblongata samples no Neospora caninum  DNA was detected. There was a significant relationship between neosporosis and maternal age (number of calvings), abortion history and the presence of dogs in the herd. Conclusions: The results showed a significant association between the infection and the number of abortions in the examined cows; As a result it seems that neosporosis could be an important factor in epidemic abortions in Arak city’s dairy farms which requires continuous monitoring and implementation of prevention programs in the dairy industry.