OBJECTIVE Because of the proximity of the inguinal lymphatics and the femoral vessels, lymph vessel manipulation during inguinal dissection is unavoidable, and this project was undertaken to evaluate the consequences. METHODS Thirty-five greyhound dogs underwent popliteal lymph node dissection, cannulation with microvascular silastic tubing, and infusion of 2.5% Patent blue violet (Sigma Chemical Co., St. Louis, Mo.) (visual enhancement) and technetium 99m-labeled human serum albumin (HSA). Animals underwent inguinal exploration with no manipulation (group 1; n = 9), local lymphatic ligation (group 2; n = 11), or radical excision and ligation (group 3; n = 15) of the inguinal lymph vessels. Lymphatic flow was calculated by 99mTc-HSA clearance (counts per minute) at the popliteal, inguinal, and iliac regions, before and after lymph vessel manipulation and was converted into percent change between the regions. RESULTS There was statistically reduced intralymphatic radioactivity in groups 2 and 3 compared with group 1 (p < 0.001; Student t test), whereas there was no significant difference between groups 2 and 3. CONCLUSIONS This demonstrates that lymphatic flow in this experimental model is significantly reduced when major channels are identified and ligated, although radical obliteration does not reduce flow more significantly than local ligation, implying that there is an alternate pathway for lymph flow.