Keel, M. K., Keeler, S., Brown, J., Fenton, H., Munk, B., Gerhold, R., … & Nemeth, N. (2020). Granulomatous Inflammation of the Muzzle in White-Tailed Deer (Odocoileus virginianus) and Mule Deer (Odocoileus hemionus) Associated With Mannheimia granulomatis. Veterinary Pathology, 0300985820948825.

Study Highlights:

A condition involving swollen muzzles was identified in 25 white-tailed deer (Odocoileus virginianus) and 2 mule deer (O. hemionus).

Microscopic lesions consisted of severe, granulomatous or pyogranulomatous inflammation of the muzzle, nasal planum, and upper lip, as well as similar but less severe inflammation of the hard palate.

Amplification and sequencing of the bacterial 16S rRNA gene from tissues of affected deer resulted in the identification of Mannheimia granulomatis.

Laser capture microdissection was used to confirm that the colonies in the inflammatory foci were M. granulomatis.

It is unclear if this is an emerging infectious disease of deer, or if it is a sporadic, uncommon condition that has only recently been recognized.