Intravenous injection of allogenic canine mesenchymal stem cells in 40 dogs: A safety assessment in veterinary clinical trials

Abstract This study aimed to evaluate the adverse effects of allogeneic mesenchymal stem cell (MSC) transplanted via intravenous infusion in dogs and examine their long-term safety, including tumorigenesis. This study conducted a retrospective analysis of various clinical assessments, including physical examination, blood tests, and radiographs, and monitored the formation of neoplasms during a 6-month follow-up period in 40 client-owned dogs that received intravenous infusion of adipose tissue-derived MSCs (AT-MSCs) for the treatment of various underlying diseases between 2012 and 2018. No significant adverse effects of MSC therapy were detected by clinical assessment, blood tests, or radiographic examination in the 6-month follow-up period after the first MSC treatment. Additionally no new neoplasms were observed during this period. This study is the first to evaluate the long-term (≥ 6 month) safety aspects and risk of tumorigenesis for intravenous allogenic AT-MSC infusion. These results suggest that allogenic AT-MSC infusion can be relatively safe therapeutic approach in dogs.