Experimental infections in young red deer<i>(Cervus elaphus)</i>with a bovine and an ovine strain of<i>Mycobacterium avium</i>subsp<i>paratuberculosis</i>

Abstract

The ovine strain of M. ptb used in this study was less virulent for red deer than the bovine strain. The correlation between dose of the bovine strain and the severity of lesions suggests that clinical Johne's disease in yearling red deer likely results from high oral challenge with a bovine strain whilst they are young. The minimum oral infective dose may be close to 10(3) cfu for this bovine strain.