Granulomatous rhinitis by Neoconidiobolus lamprauges in a mule

Abstract

ABSTRACT: Conidiobolomycosis has a wide distribution, predominantly in humid tropical regions, affecting several species with significant mortality rates. The genus Conidiobolus is now divided into four genera: Capillidium, Conidiobolus, Microconidiobolus, and Neoconidiobolus. There are no confirmed reports of infection by these fungi in Equidae in Brazil. We present a rhinofacial rhinitis caused by Neoconidiobolus lamprauges in a mule from Rio de Janeiro, Brazil. The mule presented bilateral semi-occlusion of the nostrils, difficulty breathing, and weight loss. The histological examination of the nostril biopsied mass revealed multifocal necrotizing areas with nonstained images of fungal hyphae in the Splendore-Hoeppli reaction and surrounded by macrophages, eosinophils, neutrophils, and multinucleated giant cells. The Grocott methenamine silver staining revealed thin-walled, rarely septated, irregular branching hyphae, with a varying diameter of 12 μm (± 3.63 μm), and terminal ballooning dilations. The determining etiology of this rhinitis was based on the hyphae staining by immunohistochemistry and by amplifying the DNA fragment of N. lamprauges by polymerase chain reaction. Conidiobolomycosis should be included in the differential diagnosis of the causes of rhinitis in equids, mainly in tropical regions.