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
Equine strangles is an enzootic disease of horses characterized by a regional or generalized suppurative lymphadenitis associated with an upper respiratory infection. The etiologic agent is a beta-hemolytic streptococcus, Streptococcus equi (S. equi). Reports indicate that no primary viral infection or abrasion of the respiratory mucosa is needed to produce the disease. The disease occurs in mostly young, non-exposed, non-vaccinated horses.
Reile, London J. and Genetzky, Roger M.
"Equine Strangles: A Brief Overview,"
Iowa State University Veterinarian: Vol. 45
, Article 3.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol45/iss1/3