First Detection of Anti-Besnoitia spp. Antibodies in Equids in Israel and the Palestinian Authority.

Besnoitia is a tissue cyst forming coccidia, which affects multiple host species worldwide. Equine besnoitiosis is characterized mainly by generalized skin lesions and cysts in the scleral conjunctiva. Recent reports revealed exposure to Besnoitia in equines in Europe and the United States. However, the exposure to Besnoitia spp. in the Israeli equine population was never investigated. The aim of this study was to evaluate the seroprevalence and associated risk factors for besnoitiosis in equids in Israel. A cross-sectional serosurvey was performed using serum samples of apparently healthy horses (n = 347), donkeys (n = 98), and mules (n = 6), and exposure to Besnoitia spp. was determined by an immunofluorescent antibody test (IFAT). Anti-Besnoitia spp. antibodies were detected in 17.7% equids, 6.9% horses, 33.3% mules, and 55.1% donkeys. The seroprevalence in donkeys was significantly higher than in horses (p < 0.001). A significant association between the geographic location and seropositivity was found both in horses and donkeys, which was significantly higher (p = 0.004) in horses sampled in southern Israel, and donkeys sampled in Israel versus the Palestinian Authority (p < 0.001). This is the first serosurvey of Besnoitia infection in equines in Israel, and the results are consistent with reports from Europe. The clinical significance of equine besnoitiosis should be further investigated.

Neospora spp. Seroprevalence and Risk Factors for Seropositivity in Apparently Healthy Horses and Pregnant Mares.

Equine Neospora infection has been linked to neurological disorders and infertility in horses. This study looked into the risk factors for infection and the exposure to Neospora spp. in horses. The study was performed in two independent populations in Israel. The first consisted of apparently healthy horses, and the second consisted of mares examined during pregnancy and after parturition. Sera samples collected from horses and mares were tested for Neospora exposure by the indirect fluorescent antibody test (IFAT). The study revealed seroprevalence of 24% in apparently healthy horses and 66.4% and 48.6% in mares during gestation and after parturition, respectively. Among the investigated risk factors, older age (p = 0.026) and housing in both stalls and paddocks (p = 0.033) in apparently healthy horses, and Arabian breeds (p = 0.005) in pregnant mares, were found to be significantly associated with Neospora spp. seropositivity in univariable, but not multivariable, statistical analysis. This study revealed high exposure of equines to Neospora parasites, especially mares. Horse farm management, in combination with active surveillance, including serological testing and follow up, could help reduce the spread of the parasite among horses in endemic areas.

The involvement of protozoan parasites in sheep abortions - A ten-year review of diagnostic results.

Abortions in sheep flocks affect animal health and lead to significant losses in productivity, with severe economic consequences. In recent years, the role of protozoan parasites as the cause of ovine abortions has been significant. Here, the diagnosis of infectious causes of abortions in sheep in Israel in the last decade is reviewed, focusing on parasitic pathogens. Analysis of the serological data of sheep sera (including aborted fetuses) submitted for diagnoses between 2010 and 2019 revealed overall seroprevalence of 67.4 % and 46.7 % for Neospora spp. and Toxoplasma gondii respectively, with high rates of co-exposure (32.4 %). The seroprevalence of T. gondii was higher in aborting ewes than in pre-sale examinations (48.2 % and 28.9 %, respectively (P < 0.001)). The seroprevalence of Neospora spp. was significantly higher than the seroprevalence of Toxoplasma (P < 0.001), and was similar in samples from aborting ewes and in samples from pre-sale examinations. In addition, the presence of anti-Neospora spp. antibodies was the most prominent finding diagnosed in aborted fetuses (22.9 % of aborted fetuses, significantly higher than any other organism, P < 0.001). The results of this study demonstrate that in endemic areas the seroprevalence of N. caninum in sheep may be high, and should be considered as an important cause of abortions. However, since the seroprevalence is high even in non-aborting ewes, in order to determine the causative agent of abortion in endemic flocks, a comprehensive epidemiological investigation is warranted.

The Effect of Vaccination with Neospora caninum Live-Frozen Tachyzoites on Abortion Rates of Naturally Infected Pregnant Cows.

Neosporosis is a major cause of abortions in cattle worldwide. Recently a live attenuated vaccine showing promising results in preventing abortions, when administered at mid-pregnancy to seropositive cows, was developed. In this study, vaccination with 2 × 108 live frozen N. caninum tachyzoites (NcIs491) was used to immunize naturally infected seropositive pregnant dairy dams. The study was performed under field conditions in four herds, and a follow-up of three subsequent pregnancies was analyzed. A total of 1136 cows were serologically examined. Total seroprevalence was 41.4%, with 25.1% of the cows having titers of 1:800 or higher. Abortion rates were significantly higher in cows with high antibody titers (≥1:800) for two consecutive pregnancies. Vaccination was administered to 114 out of 285 cows with antibody titers higher than 1:800. Immunization resulted in lower abortion rates at three of the farms. Vaccine efficacy ranged from -19.8% to 75% at different farms, with overall efficacy of 28.4% in all four farms and overall efficacy of 58.2% in the three farms with positive results. Our results showed different vaccine efficacy in studied farms, suggesting that frozen live vaccination may generally be an effective method to control neosporosis in cattle.