HUSBANDRY RELATED PATHOLOGICAL CONDITIONS, INCLUDING PODODERMATITIS, AVIAN POXVIRUS AND ERYSIPELAS IN A MIXED FLOCK OF PIED AVOCETS (RECURVIROSTRA AVOSETTA)

Abstract

From a collection of 84 pied avocets (Recurvirostra avosetta) originating from five different flocks and housed at ARTIS Amsterdam Royal Zoo, the Netherlands, 39 birds (46%) died. Full necropsy was performed on seventeen (44%) of the deceased birds at the Division Pathology, Utrecht University, the Netherlands. Histological findings included pododermatitis (n =17), squamous metaplasia of the uropygial gland (n = 5), inclusion bodies in the skin consistent with avian poxvirus (n = 6), and bacterial septicemia (n = 10). A bacterial culture of liver and lung revealed an Erysipelothrix (E.) rhusiopathiae infection (n = 2). After combined measures, including bedding improvement and a 51% decrease of flock density by translocating twenty-three birds to another institution, no further clinical symptoms of avian poxvirus or Erysipelas were seen. Prior to transport, these birds were vaccinated with E. rhusiopathiae, strain M2 (serotype 2) (Nobilis Erysipelasw, MSD Animal Health) and treated with Procaine penicillin (Depocillinw, MSD Animal Health) twice. A booster vaccination was given four weeks later. No side effects were observed after both vaccinations and since then no further disease cases occurred. Two months later, one of these birds died of trauma. At necropsy no signs of infectious diseases were found. Stress of mixing flocks, associated with increased infection risk and an increased population density, combined with soil-induced pododermatitis likely contributed to clinically overt avian poxvirus and Erysipelas infection. Improvement of substrate, hygiene measures and flock size reduction were successful in mitigating disease. This paper highlights the importance of low densities, natural bedding, and the prevention of pododermatitis and stress for general health and welfare in this species. Erysipelas vaccination can be safely administered to pied avocets. However, the efficacy of this vaccination remains unclear. This is the first report of clinical cases involving both avian poxvirus and Erysipelas infections in pied avocets.