Camelidae and Cervidae Listeriosis Study Guide

Overview and Clinical Importance

Listeriosis (also known as "circling disease" or "silage sickness") is a sporadic bacterial infection caused by Listeria monocytogenes, a gram-positive, facultative intracellular, non-spore-forming coccobacillus. While listeriosis is well-documented in traditional ruminants (sheep, goats, cattle), it occurs with

lower prevalence in camelids (llamas, alpacas) and cervids (deer species), but remains clinically significant due to its high mortality rate and zoonotic potential. The encephalitic form is the most commonly recognized presentation in these species, characterized by asymmetric brainstem lesions and cranial nerve deficits.

Etiology

Causative Agent

Listeria monocytogenes is the primary pathogen responsible for clinical listeriosis in camelids and cervids. Key characteristics of this organism include: