Neospora caninum is an apicomplexan parasite with a broad geographical distribution and a complex life cycle. It can cause infectious abortions in a variety of animals in the major livestock-producing nations, resulting in huge economic losses to the livestock industry. Shanxi Province in north China is one of China’s important livestock-producing provinces, but the data on the prevalence of N. caninum in sheep and goats in this province was not available prior to the present investigation. To fulfill this gap in our knowledge, serum samples were collected from 504 sheep and 300 goats across 11 cities representing three distinct geographical regions of Shanxi Province. A commercially available indirect enzyme-linked immunosorbent assay (iELISA) kit was used to determine the N. caninum prevalence by detecting N. caninum-specific IgG antibodies. Results showed that a total of 24 sheep (4.8%; 95% CI: 2.9–6.6) and 8 goat samples (2.7%; 95% CI: 0.8–4.5) tested positive for N. caninum antibodies. Geographical distribution was identified as the predominant risk factor influencing N. caninum infection in sheep and goats in Shanxi Province, with seroprevalence of N. caninum ranging from 0% to 16.7% across different sampling sites. This study reports the seroprevalence of N. caninum infection in sheep and goats in Shanxi Province for the first time, providing baseline data for the prevention and control of N. caninum infection in this northern province of China.

Giardia duodenalis (synonyms G. lamblia and G. intestinalis) and Blastocystis sp. are prevalent zoonotic intestinal protozoans with significant public health and economic importance. Both parasites infect various hosts, including humans and most livestock. G. duodenalis can cause infections ranging from asymptomatic carriage to clinical manifestations such as acute diarrheal disease, growth stunting and malabsorption, whereas Blastocystsi sp. infection is often asymptomatic and its pathogenicity remains debated. Following the rapid expansion of modern equine industries (horse racing, equestrian sports, production, and tourism), concern about the spread of parasitic diseases caused by human–horse contact has gradually increased. In this study, 631 horse fecal specimens were collected from three geographical localities in Shanxi Province, North China. The prevalence and genetic characteristics of the two parasites were determined by amplification of multiple genetic loci (tpi, triosephosphate isomerase; gdh, glutamate dehydrogenase; bg, beta-giardin) for G. duodenalis and the small subunit ribosomal RNA (SSU rRNA) gene for Blastocystis sp. Overall, the prevalence of G. duodenalis and Blastocystis sp. in horses in Shanxi Province was 7.9% and 0.8%, respectively. Sequence analysis identified three assemblages (A, B, and E) of G. duodenalis and two subtypes (ST1 and ST5) of Blastocystis sp. in horses; assemblage B and subtype ST1 were detected more frequently than the other types (subtypes) in this data set. This study is the first to report G. duodenalis and Blastocystis sp. infections in horses in Shanxi Province, and these findings provide baseline molecular epidemiological data for horses in Shanxi Province and support continued hygiene management to reduce potential zoonotic transmission.

Trichomonads include species of veterinary and zoonotic importance, yet infections with trichomonads in horses remain uncharacterized in Shanxi Province, Northern China. In the present study, we conducted a molecular survey of Tetratrichomonas buttreyi and Pentatrichomonas hominis using 631 horse fecal samples collected from Datong, Taiyuan, and Yuncheng cities in Shanxi Province between March and June 2023. Nested PCR assays targeting the small subunit ribosomal RNA (SSU rRNA) gene were used to detect the two trichomonad species. The overall molecular prevalences were 3.7% (23/631; 95% CI, 2.5–5.5%) for T. buttreyi and 0.8% (5/631; 95% CI, 0.3–1.9%) for P. hominis. T. buttreyi prevalence differed significantly by region and management mode but not by age or sex. P. hominis was detected only in Datong City, resulting in a significant regional difference; however, age, sex, and management mode were not significantly associated with P. hominis prevalence. Five representative T. buttreyi sequences and one representative P. hominis sequence were obtained in the present study. Among these sequences, two T. buttreyi sequences shared 100% nucleotide identity with reference sequences from pigs, cattle, and horses; three showed only minor nucleotide variation. The representative P. hominis sequence clustered with the zoonotic genotype CC1, suggesting that horses may form part of the broader host network of P. hominis, though further work is needed to establish horses’ reservoir competence or confirm their role in the transmission. These findings provide the first molecular evidence of T. buttreyi and P. hominis in horses from Shanxi Province, and establish a baseline for future surveillance and One Health risk assessments.