Successful treatment of disseminated cutaneous phaeohyphomycosis in a dog

A 7-year-old castrated male Whippet developed deep ulcerative skin lesions whilst receiving immunosuppressive doses of prednisolone and cyclosporine for the treatment of immune-mediated haemolytic anaemia. The lesions were determined to be a phaeohyphomycosis, caused by Curvularia lunata. The dog was treated with a combination of systemic antifungals and weaning off immunosuppressants and made a complete recovery. To the authors' knowledge, this is the first case report of the successful treatment of disseminated cutaneous phaeohyphomycosis in a dog.     

Eumycetoma and disseminated phaeohyphomycosis in a Sumatran tiger

A 16-y-old female Sumatran tiger (Panthera tigris sumatrae) was evaluated for hyporexia. Examination revealed chronic kidney disease and a large subcutaneous axillary mass with draining tracts that contained numerous small black grains. Histologic examination revealed the presence of intralesional fungal hyphae. Persistent hyporexia and pyogranulomatous disease, as well as progressive cachexia and azotemia occurred despite treatment, and euthanasia was performed. Disseminated phaeohyphomycosis was diagnosed on postmortem examination, additionally affecting various lymph nodes, the nasal cavity, mesenteric adipose tissue, abdominal aorta, pericardium, and kidney. Fungal culture from a deep-tissue sample isolated a pure growth of Curvularia sp., a dematiaceous opportunistic fungus able to cause eumycetomas and/or phaeohyphomycosis. Phaeohyphomycosis is a rare but emerging condition, not previously reported as disseminated disease in an exotic carnivore, to our knowledge. Aggressive systemic antifungal treatment was unsuccessful, likely complicated by diagnostic challenges and concurrent renal disease. The presence of a swelling with abundant grains exiting draining tracts should direct clinicians to the diagnosis of a mycetoma, warranting early and aggressive treatment.     

A case of feline phaeohyphomycosis due to Fonsecaea pedrosoi

The first report of a case of feline phaeohyphomycosis due to Fonsecaea pedrosoi is presented. Fonsecaea pedrosoi is an aetiologic agent of both human phaeohyphomycosis and chromoblastomycosis. In our cat, the lesion was confined to the skin and appeared as a firm swelling on the bridge of the nose. Diagnosis was based on histological examination of a cutaneous biopsy and fungal culture of a tissue sample on Sabouraud's dextrose agar. Further diagnostic tests failed to reveal an underlying immunosuppression. Two treatment cycles with itraconazole, at the oral dose of 5 mg kg-1 given twice daily, induced complete clinical remission, but relapses occurred.     

Cladosporium cladosporioides‐complex infection in a mixed‐breed dog

A 3‐year‐old female mixed‐breed dog was referred with a 2‐day history of serious dyspnea, coughing, lethargy, anorexia, and a low‐grade right anterior lameness. At presentation, the dog had an increased respiratory rate, dull heart and lung sounds, and cyanotic mucous membranes. It was hyperthermic and slightly dehydrated. Laboratory findings showed mild neutrophilia with a left shift, while serum biochemistry variables were in the normal range. However, urinalysis revealed mild proteinuria and rare erythrocytes and leukocytes on sediment examination. Thoracic radiographs showed a diffuse mixed interstitial and alveolar pattern with an air bronchogram, while appendicular radiographs showed a right humeral interrupted brush‐like periosteal reaction. Thoracic ultrasonography revealed mediastinal lymph node enlargement. Cytology from a fine‐needle aspirate of mediastinal lymph nodes revealed a pyogranulomatous lymphadenitis with numerous fungal hyphae. Culture on Sabouraud dextrose agar isolated dark fungal colonies with microscopic features consistent with Cladosporium spp. Sequencing of the internal transcribed spacer region identified the fungus as a species of the Cladosporium cladosporioides‐complex.     

Environmental isolation of black yeast-like fungi involved in human infection

The present study focuses on potential agents of chromoblastomycosis and other endemic diseases in the state of Paraná, Southern Brazil. Using a highly selective protocol for chaetothyrialean black yeasts and relatives, environmental samples from the living area of symptomatic patients were analysed. Additional strains were isolated from creosote-treated wood and hydrocarbon-polluted environments, as such polluted sites have been supposed to enhance black yeast prevalence. Isolates showed morphologies compatible with the traditional etiological agents of chromoblastomycosis, e.g. Fonsecaea pedrosoi and Phialophora verrucosa, and of agents of subcutaneous or systemic infections like Cladophialophora bantiana and Exophiala jeanselmei. Some agents of mild disease were indeed encountered. However, molecular analysis proved that most environmental strains differed from known etiologic agents of pronounced disease syndromes: they belonged to the same order, but mostly were undescribed species. Agents of chromoblastomycosis and systemic disease thus far are prevalent on the human host. The hydrocarbon-polluted environments yielded yet another spectrum of chaetothyrialean fungi. These observations are of great relevance because they allow us to distinguish between categories of opportunists, indicating possible differences in pathogenicity and virulence.     

Fungal infections of the central nervous system in the dog and cat

Fungal infections of the central nervous system (CNS) in dogs and cats are uncommon. The purpose of this paper is to review the clinical signs, diagnostic tests, and therapeutic options of fungal infections of the CNS in the dog and cat. Clinical signs are dependent on lesion location and are often multifocal. Extraneural involvement is common. Antemortem diagnosis can be difficult and is definitively made via cytology, biopsy, or culture of an affected organ or cerebrospinal fluid (CSF). Magnetic resonance imaging can support a diagnosis and may assist in therapeutic decisions. Fungal serology can support a diagnosis when direct visualization of the organism is not possible. Long-term azole maintenance therapy is suggested to enhance survival and prevent relapse. Serial cerebrospinal fluid evaluation and magnetic resonance imaging may identify early relapse.     

Facial cutaneous phaeohyphomycosis associated with Alternaria infectoriae infection

Cutaneous nodular disease in the horse is relatively rare and usually associated with arthropod bites, dermal hyperplasia and inflammatory or neoplastic infiltrates. Equine phaeohyphomycosis, particularly alternariosis, has been previously described in the literature and is usually associated with Alternaria alternata. In this article we report a case of phaeohyphomycosis caused by a member of Alternaria section Infectoriae in a horse. To our knowledge this is the first time that this organism has been identified in equids. Despite A. Infectoriae being commonly isolated in individuals receiving immunosuppressive therapy and/or suffering from Cushing's syndrome, we could not determine a link between pituitary pars intermedia dysfunction and fungal infection in this case. The mare responded well to surgical excision of the cutaneous lesions and made a full recovery.