An outbreak of toxoplasmosis in an aviary collection of Nicobar pigeons (Caloenas nicobaria) : clinical communication

R.D Last,H.L Shivaprasa

doi:10.4102/jsava.v79i3.263

Abstract

Three out of 10 Nicobar pigeons (Caloenas nicobaria) in an aviary collection in South Africa were found dead with no presenting clinical symptoms. Histological examination of formalin-fixed tissues from all these birds revealed necrotic foci in various visceral organs (liver, spleen, heart, kidney and lungs), plus diffuse pulmonary congestion and oedema with vasculitis. Numerous protozoal tachyzoites were present in all organs and there was strong positive immunohistochemical (IHC) labelling of these organisms for Toxoplasma gondii. Pathology was consistent with acute systemic toxoplasmosis as a consequence of oocyst ingestion. Feral cats were known to be a problem at the facility. Clinical toxoplasmosis is rarely reported in pigeons and this is believed to be the 1st report of toxoplasmosis in Nicobar pigeons.

Highlights

Toxoplasmosis is an uncommon, but frequently fatal parasitic disease of mammals, birds and reptiles, caused by the protozoan Toxoplasma gondii[1,8,17]
There appears to be variation amongst avian species in susceptibility to disease, with some species being fairly resistant to infection while other species seem to be highly susceptible . 1,2,6,24,27,30,33 Little has been published on clinical toxoplasmosis in pigeons, and this is believed to be the 1st report of toxoplasmosis in Nicobar pigeons (Caloenas nicobaria)
In susceptible avian species acute systemic toxoplasmosis is characterised by necrotic foci in various visceral organs, plus diffuse pulmonary congestion and oedema with vasculitis[1,9,10,12,15,17]

Summary

Introduction

Toxoplasmosis is an uncommon, but frequently fatal parasitic disease of mammals, birds and reptiles, caused by the protozoan Toxoplasma gondii[1,8,17]. In birds that survive long enough to develop adequate specific cell-mediated immunity, tachyzoite replication is arrested and bradyzoite-filled aVetdiagnostix – Veterinary Pathology Services, P.O. Box 13624, Cascades, 3202, South Africa. CASE HISTORY A bird park in Durban, KwaZulu-Natal, South Africa, had a collection of mixed age and sex Nicobar pigeons that were housed in a single display flight.

Results

Conclusion