Back in the day, Big tobacco exposed sheep to smoke by sticking tracheotomy tubes down their throats.
"Exposure of Sheep to Smoke by way of a Tracheostomy Tube." Truth Tobacco Industry Documents. Oct. 1970. Chart, Graph.http://legacy.library.ucsf.edu/tid/mfe81e00/pdf?search=%22sex%22
Osdene, T.S. "Visit to Huntingdon Research Center, Huntingdon, England." Truth Tobacco Industry Documents. 10 Apr. 1970. Report.http://legacy.library.ucsf.edu/tid/zej97e00
Coleman, Frank Philip. "Application for Research Grant: Effects of Prolonged Inhalation of Cigarette Smoke on the Respiratory Tract of Sheep." Truth Tobacco Industry Documents. 07 Apr. 1955. Application.http://legacy.library.ucsf.edu/tid/mrz8aa00