While the technique of isolated organ and limb perfusion in humans, pioneered by Ryan, Creech, et al.,1-4 has been employed in cancer chemotherapy for several years,5-10 controlled studies with this modality, either experimental or clinical, have been few. In the human, variables such as size, age, location, degree of malignancy of tumors, and host factors preclude the attainment of precise information. Data obtained in the laboratory11-16 relevant to perfusion of dogs has been primarily concerned with perfusion techniques and the toxic effects of antitumor drugs on normal tissues. Because of the rare spontaneous tumor occurrence and inability to grow transplanted tumors in such animals, perfusion of tumors in vivo has not been possible. Knock17 and Buckner et al.18 described rabbit limb perfusion, the report of the former being principally a description of technique, while that of the latter is confined to an evaluation of perfusion