II. Pulmonary Neoplasms

Abstract

Of 86 dogs trained to smoke through a tracheostoma, 12 dogs (group F) smoked filler-tip, 24 (group H) and 38 (group h) smoked non-filter cigarettes, and 12 (group l), half as many non…filter cigarettes.. Eight dogs (group N) never smokedm By day 875, none of the N dogs, 2 F dogs, 2 L dogs, 12 H dogs, and 12 h dogs had died, and the remaining N, F, L, and H dogs were killede Noninvasive bronchiolo-alveolar tumors were found in dogs of all five groups. Invasive bronchiolo-alveolar tumors were found only in H and h dogs: in two of 12 group h and group H dogs, respectively, which died, and eight of 12 group H dogs which were killed., One extended to and four into the pleura. Early invasive squamous cell carcinoma was found in bronchi of two of group H dogs which were killed.