Background: Benzimidazole (BZ) resistance in the gastrointestinal nematode Haemonchus contortus is a major constraint to sheep production worldwide. However, data on the prevalence and molecular mechanisms of resistance in Yili Prefecture, Xinjiang—a key livestock region in Northwestern China—remain limited. This study aimed to determine the frequency of BZ resistance-associated single nucleotide polymorphisms (SNPs) in H. contortus populations from Zhaosu and Tekesi counties. Methods: Adult male worms (n = 150) were collected from naturally infected sheep at local abattoirs. Species identity was confirmed morphologically by sequencing the internal transcribed spacer 2 (ITS-2) region. A 385 bp fragment of the isotype-1 β-tubulin gene was amplified and sequenced to detect SNPs at codons 167 (F167Y), 198 (E198A), and 200 (F200Y). Results: The F167Y mutation was absent in all individuals. In contrast, the E198A mutation occurred at exceptionally high frequencies, with resistant allele frequencies (RAF) of 64.7% in Zhaosu and 52.7% in Tekesi. The F200Y mutation showed clear geographical variation: it remained low in Zhaosu (RAF = 9.3%) but was substantially higher in Tekesi (RAF = 33.3%). Haplotype analysis revealed that resistance in Zhaosu was driven primarily by the E198A mutation, whereas the Tekesi population exhibited complex patterns of co-selection of both E198A and F200Y, with a high proportion of double-heterozygous individuals (29.3%). Conclusions: This study provides comprehensive molecular evidence of severe BZ resistance in H. contortus populations from Zhaosu and Tekesi counties, Yili Prefecture. The marked predominance of the E198A mutation, together with the emergence of multi-locus resistance in Tekesi, indicates a rapid escalation of resistance beyond historical levels. These findings suggest that benzimidazoles are likely ineffective in this region and highlight the urgent need to revise local parasite control strategies.

Tick-borne diseases (TBDs) pose a significant global threat to both canine and public health, largely attributable to the extensive geographic distribution of ticks and their ability to harbor diverse pathogens. To evaluate regional risk, this study examined the developmental biology of a prevalent tick species in Xinjiang, China, and performed molecular surveillance for key pathogens in both tick vectors and canine hosts. Observations of reproductive biology revealed that Riphicephalus turanicus ticks could complete their development from egg to adult in approximately 50 days on laboratory rabbits, indicating a rapid lifecycle and high reproductive potential. Polymerase chain reaction (PCR)-based screening of 379 canine blood samples detected infection rates of 14.25% for Anaplasma spp., 2.64% for Hepatozoon spp., 21.64% for Rickettsia spp., and 21.90% for Babesia spp. Concurrently, screening of 184 tick samples revealed detection rates of 15.22% for Anaplasma ovis, 8.15% for Hepatozoon spp., and 21.74% for Rickettsia spp. Statistical analysis identified significant regional variation in pathogen prevalence across the surveyed locations. The BLASTn (BLAST: Basic Local Alignment Search Tool) alignment revealed high sequence identity (99.30–100%) with known strains of Babesia, Rickettsia, and Anaplasma circulating in Asia and Europe. confirming the presence of these pathogens in the local ecosystem and evolutionary linkage to global lineages. Collectively, these findings provide valuable epidemiological insight into the endemic nature of TBDs in Xinjiang and emphasize the importance of integrated tick management and sustained disease surveillance programs.

From September 2024 to September 2025, 310 blood samples from cattle (n = 151), camels (n = 44), horses (n = 71), and wild mice (n = 44) across six Xinjiang counties/cities were screened by microscopy, genus-specific PCR, sequencing, and phylogenetic analysis. Overall, 46.77% (145/310) of the samples were positive for haemoprotozoan infection. Trypanosoma spp. showed the highest prevalence (25.48%, 79/310), followed by Theileria (16.13%, 50/310) and Babesia (5.16%, 16/310). Notable host-specific patterns emerged: camels had the highest T. evansi occurrence (86.36%), while wild mice had the highest Theileria prevalence (75%). Dual infections (mostly Trypanosoma + Theileria) occurred in 8.39% (26/310) of animals, and a triple infection was found in 0.32% (1/310). Phylogenetic analysis identified T. evansi as predominant trypanosome, clustering with isolates from India and Saudi Arabia; the major piroplasms identified were T. annulata, T. equi, and an unidentified Babesia sp. This study represents the first multi-host molecular survey in Xinjiang, revealing a high infection burden, diverse parasite species, and frequent co-infections.