Equine osteoarthritis (OA) is a major cause of lameness and economic loss in horses. While platelet-rich plasma (PRP) has clinical potential, the biological effects of fresh PRP (F-PRP) and freeze-dried PRP (FD-PRP) remain insufficiently defined. This pilot study compared 25% and 50% F-PRP and FD-PRP in an interleukin-1β-induced equine cartilage-synovium explant co-culture model. PRP treatments reduced inflammatory responses, with significant downregulation of COX-2 and PGE2 expression, and 25% F-PRP showed the most consistent inhibition of nitric oxide production. PRP also significantly reduced glycosaminoglycan release and altered matrix-related gene expression; however, FD-PRP significantly upregulated MMP13, indicating a potential pro-catabolic response. Untargeted LC/MS metabolomics showed that F-PRP and FD-PRP were associated with changes in glucose, purine, amino acid, lipid, and nucleotide metabolism. Growth factor analysis further showed lower PDGF and TGF-β1 concentrations in FD-PRP than in F-PRP. Overall, F-PRP showed more consistent anti-inflammatory and matrix-protective effects, whereas FD-PRP requires further optimization and safety validation before clinical application.

This study investigated the cyathostomin species composition, anthelmintic efficacy, and potential resistance-associated mutations in Chinese grazing horses. Fecal samples were collected from 90 adult horses. Fecal egg counts (FECs) were determined using a modified McMaster method. Third stage larvae (L3) cultured from the eggs were identified to species level by PCR amplification and sequencing of the internal transcribed spacer-2 (ITS-2). The main species included Cylicocyclus nassatus and Cylicostephanus spp. However, differences in the relative abundance of less common species, including Cyathostomum pateratum and Cylicocyclus ashworthi, suggests regional variation. Anthelmintic efficacy was assessed by a fecal egg count reduction test (FECRT) following albendazole administration. Mutations at six codons of the β-tubulin iso-type-1 (tbb-iso-1) gene were screened by gene sequencing. The results showed that, despite harboring an abundant and diverse cyathostomin community, this herd remained susceptible to albendazole. Overall, this study provides baseline data on cyathostomin species composition and anthelmintic susceptibility in horses from China, contributing to global surveillance of equine cyathostomin resistance.