Some Histopathological Findings in Dead Kihansi Spray Toads in Captivity

Abstract

Raising of Kihansi spray toad (KST), Nectophrynoides asperginis, in captivity is associated with disorders that can be fatal. Since diagnosis of these disorders cannot be confirmed grossly, the current study was aimed at exploring histopathological findings in dead KSTs kept under captivity in Tanzania. Dead KSTs were immediately recovered, observed for gross changes, fixed in 10% neutral buffered formalin, processed routinely, and stained sections reviewed for histological changes. Observed infectious agents were strongyloides (25.3%), ciliates (1.7%), lungworms (0.6%), fungi (3.4%) and bacteria (5.1%) or mixed infections (9%) of these agents. Noted histopathological lesions in affected organs included infiltration of inflammatory cells, thickening of the epithelium, organ dilation, accumulation of organisms and dead tissue debris in the organs, hyperkeratosis, parakeratosis, and sloughing of the skin. Squamous metaplasia in various organs was the commonly observed non-infectious abnormality noted in 33.1% of the carcasses. It is concluded that there are several histological changes caused by infectious and non-infectious agents that are potential contributors of KST death in captivity.

Keywords: Kihansi spray toad; parasites; pathology; captivity; immunity