Chronic ulcerative dermatitis caused by Fusarium sporotrichioides

The present study describes the isolation of Fusarium sporotrichioides from a canine cutaneous ulceration. A 2-year-old male Beagle dog weighing 8.6 kg, with a history of immune-mediated hemolytic anemia (IMHA), had been treated with prednisone for 9 months. Physical examination revealed cutaneous ulceration on the left foreleg. Histopathological examination of skin samples from the ulcerative area revealed many branching hyphae surrounding neutrophils. Since itraconazole (ITZ) is recommended for miscellaneous fungal infections, the dog was treated with ITZ. However, the ulcerative lesions did not improve and after 3 weeks of treatment the dog died due to renal failure. No autopsy was performed. Since the isolate recovered from the biopsy specimen was identified as Fusarium species by morphological characteristics, the animal was diagnosed as having had an infection caused by this mould. The dog's prior prednisone treatment may have played a role in establishing the fungal infection. Comparative sequence analyses of the ITS regions of the clinical isolate with those in GenBank showed that it was 100% identical to F. sporotrichioides and less than 96% similar to ITS of other Fusarium species. Based on these findings, F. sporotrichioides was established as the etiologic agent of the canine infection, a situation that has not been previously reported in dogs, as well as humans.