Theobald Smith and animal parasitology: highlights on an anniversary.

In marking the 100th anniversary of the landmark publication in 1893 by Theobald Smith and Frederick L. Kilborne on cattle babesiosis and arthropod transmission, this article takes note of other contributions of Theobald Smith to the knowledge of a variety of parasitic organisms. Notable are his studies on the protozoan agent of avian enterohepatitis. The results of Smith's work in comparative pathology, to which he devoted his professional life, have had broad applications with economic and health benefits for domestic animals and humans.