Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
Neoplasms of the nasal and paranasal sinuses make up approximately 1% of canine tumors. These tumors are malignant in 80 % of the cases, and 60 - 75 % are carcinomas. According to most authors, adenocarcinomas are the most common nasal tumor, followed by squamous cell carcinoma. Large and medium sized dogs in the 8-10 year age group are most commonly affected. Some authors find the dolicocephalic breeds to be the most prone to develop adenocarcinoma, while others find the number of cases higher in the mesocephalic breeds. Some reports show a higher incidence of nasal adenocarcinoma in male dogs, but when correction is made for sex distribution of the number of cases seen, there is no difference in nasal tumor incidence between males and females. There is no known etiological agent for nasal adenocarcinoma, and there is no difference between urban and rural dogs with respect to nasal and sinus neoplasia.
Tuttle, Lisa E. and Grier, Ronald L.
"Nasal Adenocarcinoma in the Canine,"
Iowa State University Veterinarian: Vol. 47
, Article 8.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol47/iss1/8