Phaeohyphomycosis caused by Exophiala spinifera in two cats

The dematiaceous fungus Exophiala spinifera was isolated from a cutaneous lesion on the paw of a male domestic shorthair cat and from the nasal exudate and abscess contents from a female domestic shorthair cat. Treatment with ketoconazole (10 mg kg-1 daily) resulted in improvement in the first cat but unfortunately this animal was subsequently lost to follow-up. The second cat was treated initially by the same regimen without apparent benefit. The dose of ketoconazole was subsequently increased but finally had to be discontinued when the cat developed signs of hepatotoxicity. At this stage treatment with flucytosine (150 mg kg-1 daily) was commenced. The cat improved and cultures of nasal exudate performed 8 and 16 weeks after initiation of 5-fluorocytosine therapy were negative for E. spinifera. However, the condition recurred with granulomatous tissue appearing in each nostril and abscess formation with subsequent rupture occurring on the bridge of the nose when therapy was withdrawn. These two cases constitute the first report of E. spinifera infection in animals and of this fungal infection in Australia.