Mycobacteriosis in peafowl: Analysis of four cases

Abstract

Peafowl (Pavo cristatus), similarly to other Galliformes, are particularly susceptible to infection by Mycobacterium avium. Peafowl differ from other Galliformes in the clinical image of the infection, with dominating respiratory signs. Occurrence of severe and sustained dyspnoea in peafowl raises suspicion of mycobacteriosis, which, however, is not always easy to confirm. In the cases described here, mycobacteria were detected in direct swabs from the trachea of two individuals, and cultures were conducted on the Löwenstein- Jensen medium. In one individual, no mycobacteria were found in tracheal swabs stained by the Ziehl-Neelsen method, despite the presence of clear clinical signs. The fourth case was a young bird submitted for necropsy. The cause of death was a mechanical trauma, but scarce caseous nodules typical of mycobacteriosis were found in the liver, spleen and lungs. The Mycobacterium avium isolates obtained from those cases were compared using (CCG)4-based PCR. A high similarity of three isolates of Mycobacterium avium subsp. avium was observed, two of which were derived from peafowl originating from the same farm, while the isolate from the fourth bird differed significantly and was identified by sequencing as Mycobacterium avium subsp. paratuberculosis..