Reverse gingival venipuncture: a refined technique for serial blood collection in small rodents

ObjectiveTo assess the safety, efficacy, and repeatability of a novel blood collection technique, percutaneous reverse gingival venipuncture (RGV), across multiple rodent species, and to characterize the associated anatomy through dissection and histopathology. MethodsSuccess rate and complications of RGV were evaluated at a private practice between December 2024 and September 2025 in client-owned chinchillas (Chinchilla lanigera) (n=102), guinea pigs (Cavia porcellus) (n=78), Syrian hamsters (Mesocricetus auratus) (n=32), dwarf hamsters (Phodopus campbelli and P. sungorus) (n=4), squirrels (Callosciurus erythraeus, C. finlaysonii) (n=7), prairie dogs (Cynomys ludovicianus) (n=2), a capybara (Hydrochoerus hydrochaeris) (n=1) and a Patagonian mara (Dolichotis patagonum) (n=1). An experimental study was conducted in laboratory rats (Rattus norvegicus) (n=5), Chinese hamsters (Cricetulus griseus) (n=12), and chinchillas (n=11) from February 2026 to March 2026 to evaluate RGV success rate, serial hematology, and histopathology. ResultsThe success rate of RGV was 100% in most rodent species, but was lower in guinea pigs (44.87%, n=78) and chinchillas (64.60%, n=113). No animals experienced clinical complications. No significant changes in serial hematology were appreciated in Chinese hamsters (n=6) on days 0, 7, and 14. Histopathology did not reveal any complications. ConclusionsRGV in anesthetized rodents is safe, effective, minimally invasive, and repeatable, yielding clinically relevant blood volumes with precise control and minimal risks. Clinical RelevanceRGV may facilitate more routine hematology and chemistry analysis in rodents by veterinary practitioners, with few risks and complications. In research settings, RGV may improve animal welfare and contribute to refinement and reduction.