Description: Corynebacterium pseudotuberculosis is a pleomorphic, Gram-positive and facultative intracellular rod, causing suppurative conditions in several species, as horses, goats, sheep, cattle, swine, buffaloes, llamas, camels, deer, hedgehogs, laboratory animals and occasionally in humans. C. pseudotuberculosis is classified into two biotypes according to host preferences and ability to reduce nitrate. Nitrate-negative biovar Ovis strains predominantly infect small domestic ruminants and may infect cattle, while nitrate-positive biovar Equi strains usually infect horses, cattle and water buffalo.