ObjectiveTo develop and describe a minimally invasive technique for excisional biopsy of the axillary lymph nodes in dogs.Study designDescriptive cadaver and clinical case series.AnimalsFour canine cadavers and three clinical patients.MethodsA 3D computed tomographic reconstruction of the canine axilla was used to identify an optimal avenue of approach to the lymph nodes. This approach was refined using endoscopic techniques in four cadavers (six procedures) and potential surgical hazards, landmarks, and the surgical time required for excisional biopsy of the nodes was recorded. The procedure was then performed in three clinical cases.ResultsAxillary lymph node removal was achieved using an endoscopic technique with surgical times of 58 and 35 minutes in two of three clinical cases. The third case required conversion to an open approach after endoscopic identification of the node. No major complications were encountered.ConclusionExcisional biopsy of the axillary lymph nodes can be performed successfully using a minimally invasive technique in the dog. Further investigation in clinical cases is needed to determine the risks and complications of this procedure.Clinical significanceMinimally invasive excisional biopsy of the axillary lymph nodes in dogs can be performed and may have a role in assisting with staging and local disease control in oncologic cases.