An outbreak of Yersinia pseudotuberculosis at a zoo aviary in central California: case series and field investigation.

Here, we detail the pathology findings in a hooded pitta (Pitta sordida), a beautiful fruit dove (Ptilinopus pulchellus), and a golden-crested myna (Ampeliceps coronatus), all housed together in a mixed-species aviary at a zoo in central California that experienced mortalities over 3 mo. Yersinia pseudotuberculosis was identified as the primary pathogen, responsible for necrotizing heterophilic and histiocytic hepatitis, splenitis, pneumonia, nephritis, myositis, myocarditis, and enteritis. We also share the results of a field investigation to identify the source(s) of Y. pseudotuberculosis infection in the aviary; no bacteria were detected in samples of water, soil, feces, earthworms, earwigs, or organs from mice and fox squirrels, leading to the suspicion that the hooded pitta was a carrier. The zoo's veterinary team implemented control measures, including an 11-mo quarantine and the acquisition of birds before the cold, rainy season, allowing them to acclimate safely. No new cases of yersiniosis occurred at the aviary in the year following the outbreak.