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Early abortion is a clinical presentation of ovine toxoplasmosis that occurs in the second week post-infection (pi), which is characterised by placental infarcts, foetal leukomalacia and absence of parasites in the placenta and foetal tissues. The pathogenic mechanism of early abortion is unknown , and descriptions of the early dynamics of T. gondii infection in pregnant sheep are scarce. The aim of this study was to investigate the presence of lesions and parasite DNA in the small intestine, mesenteric lymph nodes and placenta/foetus, that could be key during the first week after oral infection in sheep at mid-pregnancy. In the small intestine, lesions were rare and parasite DNA detection rates were low (3–8%), with the highest parasite DNA detection and burden found on day 6 pi in the Peyer’s patches of the medial jejunum. In the mesenteric lymph nodes, adenomegaly and microscopic lesions were mainly observed on day 6 pi. Parasite DNA was detected in 11% and 61.2% of the samples from mesenteric lymph nodes on days 3 and 6 pi, respectively, with higher parasite DNA detection rates and burdens in the medial and distal jejunal lymph nodes on day 6 pi. In the placentomes, on day 6 pi, gross lesions were not observed, although significant histological changes, such as endothelial activation and vascular thrombosis, were found in 18.6% and 8.3% of the placentomes, respectively. These findings lay the groundwork for future research aimed at elucidating the precise mechanisms underlying early abortions following T. gondii infection in pregnant sheep.

Background Toxoplasmosis not only leads to abortion in humans but also in herbivores, which causes significant financial and quality-adjusted life-year losses. The present study aimed to determine the prevalence of toxoplasmosis in aborted fetuses via serological and molecular assays. Moreover, the genotypes of the obtained isolates were detected. Methods Serological and molecular methods were used to study aborted fetuses from Bojnourd City, North Khorasan Province, Iran, which included 52 ovines and 16 bovines. Nested PCR of the B1 gene was used to detect parasite DNA in brain tissues. The PCR-RFLP method for the GRA6 gene was used to determine the genotype of T. gondii. Results Out of 68 aborted fetuses, 16.1% showed the presence of anti- T. gondii IgG. Among these, 11.7% were identified in bovine fetuses and 4.4% in ovine fetuses. Additionally, two (2.94%) samples of ovine tested positive for anti- T. gondii IgM. Our PCR analysis detected parasite DNA in two cases (2.94%) among 11 IgG-positive samples. All obtained isolates belong to type I of T. gondii . Conclusion Infection with Type I of T. gondii during the neonatal period may partly be responsible for abortion and economic losses in livestock farming in our studied region. To understand the molecular epidemiology and genotypes of T. gondii associated with abortion, further evaluation of aborted samples from different geographical locations is necessary.

Neosporosis and toxoplasmosis are important parasitic causes of abortions in small ruminants. This study verified the occurrence of these diseases in sheep fetuses from Santa Catarina State, Southern Brazil from 2015 to 2022. Sheep fetuses were necropsied with organ sampling for histopathology, and polymerase chain reaction (PCR) for Neospora caninum and Toxoplasma gondii using the Nc5 and SAG2 targets, respectively, in frozen brain tissue. Microbiological culture and RT-PCR for Pestivirus were conducted to discard other abortion causes. One positive fetus for toxoplasmosis was genotyped using multiplex multilocus nested PCR-RFLP (Mn-PCR-RFLP) with ten genetic markers. Fifty-five sheep fetuses were evaluated, with 10 (18.2%) cases of neosporosis and 7 (12.7%) cases of toxoplasmosis, comprising six and four flocks, respectively. Macroscopically, neosporosis abortions exhibited fetal mummification, maceration, and arthrogryposis. Toxoplasmosis abortions showed fetal mummification and maceration. The neosporosis abortions included lymphoplasmacytic myositis (70%; 7/10) and myocarditis (60%; 6/10), in addition to necrotizing encephalitis and gliosis (50%; 5/10). Toxoplasmosis abortions included lymphoplasmacytic necrotizing encephalitis (71.4%; 5/7), lymphoplasmacytic myositis (42.8%, 3/7), and myocarditis (14.3%; 1/7). Through PCR, N. caninum and T. gondii were detected in 6 (60%) and 5 (71.4%) fetuses, respectively. In one fetus, T. gondii genotyping was conducted, which was characterized as atypical genotype ToxoDB #98. All of the cases were negative for Pestivirus and bacterial agents. This study establishes the occurrence of these diseases as causes of abortions, malformations, mummification, and fetal maceration in sheep, with the characterization of an atypical T. gondii genotype in one of the fetuses.

Background Cattle abortion, which may be caused by different infectious agents, harms milk and meat production, animal health, and ultimately rural economies. Despite the existence of a national control program for cattle brucellosis since 1995, abortion remains a major concern for cattle breeders in Algeria even among officially recognized cattle Brucellosis-free herds. The objective of this study is to investigate i: the abortion rate among officially recognized cattle Brucellosis-free herds, ii: the seroprevalence of some abortive infectious agents within cattle Brucellosis-free herds, iii: evaluate the abortion risk factors associated with the seropositivity of the investigated abortive agents among brucellosis cattle-free herds. Results The present study reveals an abortion rate at the herd and the individual level of 47, 36% (20/38) and 29, 06% (50/172) respectively. Herd seroprevalences were as follows: neosporosis (31,57%), toxoplasmosis (28,94%); chlamydiosis (Chlamidophila abortus) (15,78% ); Q fever ( Coxiella burnetii ) (47,36%); Bovine viral diarrhea (BVD) (60,52%) and infectious bovine rinotracheitis (IBR) (42,10%). The risk factor analysis using a multivariable logistic regression model at the herd level showed that seropositivity to neosporosis (OR = 1, 11, CI: [0,85 − 1,19]); toxoplasmosis (OR = 1,95, CI: [1,22 − 2,84]); IBR (OR = 1,78, CI: [1,59 − 2,79]); BVD (OR = 1,65, CI: [1,86 − 3,43]); Q fever (OR = 1,51, CI: [1,42 − 2,53]) is a risk factor for abortion. Additionally, our findings reveal that the presence of co-infection is also a risk factor for abortion among Algerian Brucellosis-free herds. The risk for abortion at the herd level was 1,41 times higher for double and triple-infected herds and 1,65 times higher for quintuple-infected herds compared to negative. Moreover, managerial factors, such as hygiene practices on farms, the presence of primiparous cows, and mixed breeding livestock, were identified as additional risk factors for abortion. Conclusion Based on these results, particular attention should be given to the studied abortive agents to strengthen the prevention and control plan. Furthermore, establishing some preventive measures such as quarantine and biosecurity could help reduce infections in dairy farms.

Neospora caninum is a commonly diagnosed cause of reproductive losses in farmed ruminants worldwide. This study examined 495 and 308 samples (brain, heart and placenta) which were collected from 455 and 119 aborted cattle and sheep fetuses, respectively. DNA was extracted and a nested Neospora ITS1 PCR was performed on all samples. The results showed that for bovine fetuses 79/449 brain [17.6% (14.2–21.4)], 7/25 heart [28.0% (12.1–49.4)] and 5/21 placenta [23.8% (8.2–47.2)] were PCR positive for the presence of Neospora DNA. Overall 82/455 [18.0% (14.6–21.7)] of the bovine fetuses tested positive for the presence of N. caninum DNA in at least one sample. None (0/308) of the ovine fetal samples tested positive for the presence of Neospora DNA in any of the tissues tested. The results show that N. caninum was associated with fetal losses in cattle (distributed across South-West Scotland), compared to sheep in the same geographical areas where no parasite DNA was found. Neospora is well distributed amongst cattle in South-West Scotland and is the potential cause of serious economic losses to the Scottish cattle farming community; however, it does not appear to be a problem amongst the Scottish sheep flocks.

Background Neospora caninum is an obligate intracellular protozoan that is well established as a causative agent of abortion in dairy cattle worldwide. Objectives The objective of this study was to determine the role of N. caninum infection in the abortion in dairy cattle in the Khorasan Razavi Province, Iran. Methods From 2022 to 2024, 105 aborted bovine foetuses were collected from dairy cattle in Khorasan Razavi province. Brain samples of aborted foetuses were tested using nested PCR and histopathological examination. In addition, blood samples were collected from dairy cattle that had aborted PCR‐positive foetuses and were analysed using enzyme‐linked immunosorbent assay (ELISA). Results and Conclusions In the present study, N. caninum infection was detected in 24.76% (26 out of 105) of aborted bovine foetuses by nested PCR analysis. The brain tissues of 20 bovine‐aborted foetuses were only suitable for histopathological examination. Lesions of the central nervous system were severe hyperaemia, perivascular cuffing, astrogliosis, mild encephalitis and focal necrosis. One foetus exhibited a 32‐µm N. caninum cyst within the brain tissue. IgG antibodies against N. caninum were identified in all dairy cattle that aborted infected foetuses through ELISA testing. Molecular, histopathological and serological findings strongly suggest that N. caninum plays a significant role in bovine abortion in dairy cattle in Khorasan Razavi Province, northeast Iran. Aborted bovine foetuses were collected from dairy cattle in Khorasan Razavi province. Brain samples of aborted foetuses were tested to detect N.caninum infection using nested PCR and histopathological examination. In addition, blood samples were collected from dairy cattle that had aborted PCR‐positive foetuses and were analysed using ELISA .

This study reports an outbreak of oriental theileriosis in dairy cattle imported to Vietnam from Australia. Following clinical and pathological diagnoses, a total of 112 cattle blood samples were divided into three groups and tested using multiplexed tandem PCR. Group 1 were from aborted heifers in Vietnam; group 2 were from cattle before shipment from group 1 cattle and group 3 were from the same batch of cattle but transported to Taiwan. Theileria orientalis DNA was detected in 72·3% cattle. The prevalences of T. orientalis in groups 1, 2 and 3 were 77·6, 86·9 and 57·5%, respectively, and the difference in prevalence was significant between groups 1 and 3 (P < 0·0001). The infection intensities of genotypes chitose and ikeda of T. orientalis were higher in groups 1 (57 721 and 33 709, respectively) and 3 (5897 and 61 766, respectively) than those in group 2 (2071 and 6331, respectively). Phylogenetic analyses of the major piroplasm surface protein sequences revealed that genotypes chitose and ikeda determined herein were closely related to those previously reported from Australia. This first report of an outbreak of oriental theileriosis in imported cattle emphasizes improved measures for the export and import of cattle infected with T. orientalis.

Congenital infection with Toxoplasma gondii is an important cause of abortion in sheep worldwide. The cat is the definitive host of the parasite, and infected cats may shed millions of oocysts in their faeces resulting in extensive environmental contamination and an important source of infection for grazing herbivorous animals. Studies looking at development of specific antibodies in sheep, as an indicator of exposure to T. gondii, have shown that there is an increase in seroprevalence associated with age indicating that most infections in sheep occur following birth. The stage of gestation when transplacental transmission of T. gondii to the developing foetus occurs is critical in determining the clinical outcome. The importance of endogenous transplacental transmission in persistently infected ewes and its clinical importance is a subject of current debate. Ewes infected prior to mating develop immune responses that help protect against disease in a subsequent pregnancy and also against experimental challenge administered during pregnancy. Both innate and adaptive immune responses are activated following T. gondii infection and experiments involving the chronic cannulation of peripheral lymph nodes in sheep have allowed the dynamics of the immune responses to be analysed in real time. A live vaccine, Toxovax® is the only commercially available vaccine worldwide to protect against congenital toxoplasmosis.

Background Bovine theileriosis, caused by the haemoprotozoan Theileria orientalis , is an emerging disease in East Asia and Australasia. Previous studies have demonstrated transplacental transmission of various Theileria spp. but molecular confirmation of transplacental transmission of T. orientalis has never been confirmed in the field. In this study, cow-calf (< 48 h old) pairs were sampled across 3 herds; opportunistic samples from aborted foetuses or stillborn calves were also examined. Molecular (multiplex qPCR) and serological (ELISA) methods were used to determine infection prevalence and the presence of anti- Theileria antibodies in each herd. In addition, pregnant heifers and foetal calves were sampled at abattoir and tested for the presence of T. orientalis by qPCR. Results The qPCR results indicated that, even though there was a high prevalence of T. orientalis infection in cows, the rate of transplacental transmission to their calves was low, with only one newborn calf from one herd and one foetus from the abattoir testing positive for T. orientalis DNA. Five aborted foetuses and stillborn calves, 3 of which were derived from a herd experiencing a high number of clinical theileriosis cases at the time of sampling, all tested negative for T. orientalis by qPCR. This suggests that in utero infection of calves with T. orientalis may not be a major driver of abortions during theileriosis outbreaks. Temporal monitoring of 20 calves born to T. orientalis -positive mothers indicated that T. orientalis was detectable in most calves between 10 and 27 days post-partum , consistent with prior field studies on adult cattle introduced to Theileria -affected herds. There was a positive correlation between the ELISA ratio of newborn calves and their mothers within 48 h of calving; however, maternal antibodies were only detectable in some calves and only for 4–4.5 weeks post-partum . All calves displayed high parasite loads peaking at 4–8 weeks post-partum , with only some calves subsequently mounting a detectable adaptive antibody response. Conclusions These findings indicate transplacental transmission of T. orientalis appears to play only a minor role in persistence of T. orientalis infection in the field; however calves are highly susceptible to developing high level T. orientalis infections at 4–8 weeks of age regardless of whether maternal antibodies are present post-partum .

This study aimed to determine the seroprevalence and identify the risk factors associated with Neospora caninum, Bovine herpesvirus type 1 (BHV-1), and Bovine viral diarrhea virus (BVDV) infection on industrial Holstein dairy cattle farms in Isfahan province, Central Iran. Blood samples were taken from 216 apparently healthy cattle from 16 randomly selected Holstein dairy farms in the North, South, East, and West of Isfahan in the summer of 2017. The antibodies to N. caninum, BHV-1, and BVDV were detected using a commercially available ELISA kit. The overall seroprevalence for N. caninum, BHV-1, and BVDV was 19%, 72.2%, and 52.8%, respectively. The significant major risk factors of BHV-1 in cattle were identified as farm direction, age groups, parity, and milk yield by the univariate analysis (p < 0.05). The significant major risk factors of BVDV in cattle were identified as age groups, parity, milk yield, and stage of pregnancy (p < 0.05). The only significant major risk factor of N. caninum was farm direction (p < 0.05). A significant association of concurrent infection with BVDV and BHV-1 has shown in the current study (p < 0.05). This study is the first to report the risk factors for N. caninum, BHV-1, and BVDV infection in the central part of Iran and allows us to conclude that these agents are widely distributed in this region.