Stem Cell-Based Therapies in Companion Animals: Molecular Mechanisms, Clinical Applications, and Translational Perspectives

Stem cell-based therapies, as regenerative and immunomodulatory strategies, show substantial potential in companion animals through tissue repair, functional recovery, and immune modulation. Despite advances in human stem cell research, veterinary clinical translation remains constrained by small sample sizes, short follow-up periods, and non-standardized cell dosing regimens and delivery protocols. The expanding repertoire of stem cell-based modalities and technologies—including mesenchymal stem cells, induced pluripotent stem cells, extracellular vesicles, and tissue engineering—provides promising avenues for clinical application. This review summarizes recent progress in stem cell-based therapies across multiple disease systems in dogs and cats, with particular attention to the molecular mechanisms underlying regenerative and immunomodulatory effects, cross-species translational strategies, current challenges, and combinatorial therapeutic approaches in companion animals. By examining mechanistic findings alongside preclinical and early clinical evidence, this review highlights the limitations of current knowledge and identifies research priorities for evaluating the safety and efficacy of stem cell-based therapies in dogs and cats.