Conidiobolomycosis, cryptococcosis, and aspergillosis in sheep and goats: a review

Abstract

We review herein infections by Conidiobolus spp., Cryptococcus spp., and Aspergillus spp. in sheep and goats. Conidiobolus spp. are common causes of rhinitis in sheep and are less frequent in goats, in which Conidiobolus spp. also cause skin lesions. Cryptococcus spp. cause rhinitis, meningitis, encephalitis, and pneumonia in goats, and are rarely observed in sheep. Aspergillus spp. may cause rhinitis in goats, and pneumonia and mastitis in sheep and goats. Gross and microscopic lesions caused by these 3 fungal infections may be similar to each other. The diagnosis of these diseases must be based on gross and microscopic lesions, coupled with detection of the agent by immunohistochemical, molecular, and/or culture-based methods.

Case Report: Pulmonary Conidiobolomycosis in a Vietnamese Pot-Bellied Pig

“…In other species (humans, horses, sheep, goats, and dogs), conidiobolomycosis typically presents as rhinofacial or nasopharyngeal lesions ( 4 , 8 , 20 , 21 ). In sheep, as shown in endemically infected populations in Brazil, conidiobolomycosis often results in non-specific clinical signs of malaise, anorexia, weight loss, and serous/mucoid to hemorrhagic nasal discharge ( 7 , 20 , 22 ). Disseminated/systemic conidiobolomycosis is less commonly reported but has been described in humans, sheep, dogs, deer, and pigs ( 5 , 6 , 18 , 21 , 22 ).…”

“…In cases of conidiobolomycosis, diagnostic cytology (from a touch impression of a biopsy sample or from fluid from a tracheal wash, bronchoalveolar lavage, or thoracocentesis) may show eosinophilic, suppurative, and/or granulomatous inflammation with or without fungal hyphae ( 3 , 5 , 8 , 23 ). Typical histologic lesions of conidiobolomycosis in all veterinary species consist of pyogranulomatous to granulomatous inflammation, often with a prominent eosinophilic inflammatory infiltrate ( 3 , 6 , 8 , 10 , 17 , 20 ). This inflammation is centered around non-staining to slightly basophilic fungal hyphae that are surrounded by thick “sleeves” of amorphous to granular eosinophilic material, which represents Splendore-Hoeppli material (antigen-antibody complexes) and potentially eosinophil major basic protein from degranulating eosinophils ( 3 , 6 , 10 , 20 , 22 , 26 , 27 ).…”

“…Typical histologic lesions of conidiobolomycosis in all veterinary species consist of pyogranulomatous to granulomatous inflammation, often with a prominent eosinophilic inflammatory infiltrate ( 3 , 6 , 8 , 10 , 17 , 20 ). This inflammation is centered around non-staining to slightly basophilic fungal hyphae that are surrounded by thick “sleeves” of amorphous to granular eosinophilic material, which represents Splendore-Hoeppli material (antigen-antibody complexes) and potentially eosinophil major basic protein from degranulating eosinophils ( 3 , 6 , 10 , 20 , 22 , 26 , 27 ). The Splendore-Hoeppli reaction is a characteristic feature of Conidiobolus spp.…”

“…infection but can also be observed with infection by other members of the orders Entomophthorales and Mucorales as well as other types of infectious agents (including certain bacteria and parasites) ( 3 ). GMS stain highlights the hyphae and helps to reveal occasional septation and infrequent non-dichotomous branching; whereas, the hyphae often do not stain or stain only weakly with PAS stain ( 8 , 20 ).…”

“…Due to the low number of reported cases of conidiobolomycosis, there is limited evidence for effective treatments ( 5 , 20 ). Complete and aggressive surgical excision of granulomas with accompanying long-term antifungal therapy (such as itraconazole) is considered the gold standard for treatment in many species, including humans and dogs ( 5 , 21 ).…”