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
The ciliated protozoan, Buxtonella sulcata, was found in 28% of a sample of Iowa cattle in 1927, and in 32% of a sample of Louisiana cattle in 1930. As far as we can ascertain it has not been reported in American cattle since. During the summer of 1962, B. sulcata was found associated with ulcerative colitis in a cow from northeast Nebraska. This finding prompted incidence of infection in the region.
Urman, H. D. and Kelley, G. W.
"Buxtonella Sulcata A Ciliate Associated with Ulcerative Colitis in a Cow and Prevalence of Infection in Nebraska Cattle,"
Iowa State University Veterinarian: Vol. 26
, Article 11.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol26/iss2/11