Addressing Heterogeneity in Equine PRP Therapies: A Scoping Review of Methods, Evidence, and Commercial Validation

(1) Background: Platelet-rich plasma (PRP) therapy has become a cornerstone of equine regenerative medicine, yet significant methodological variability compromises reproducibility and clinical comparability. (2) Methods: This scoping review systematically mapped and analyzed peer-reviewed studies describing equine PRP preparation methods and commercial systems (2000-2024) following PRISMA-ScR guidelines. (3) Results: Twenty-four studies met the inclusion criteria, encompassing 317 horses and both manual and commercial devices. Double-spin manual protocols predominated, though centrifugation parameters, anticoagulants, and activation strategies varied widely. Methodological quality, assessed using an adapted nine-criterion framework, revealed that only 29% of studies achieved comprehensive reporting, particularly lacking platelet-yield and activation details. An additional multilingual web search identified 24 veterinary PRP kits, of which only 10 had published validation in horses, exposing a pronounced gap between marketing claims and scientific evidence. (4) Conclusions: These discrepancies underscore the need for standardized reporting, transparent characterization, and independent evaluation of PRP systems. The proposed framework aims to guide future research toward reproducible, evidence-based practices that enhance therapeutic reliability and clinical translation in equine regenerative medicine.