Case report. Maduromycosis in a horse in Western Canada

A 13-yr-old gelding which had received a severe kick on the eye 1 yr previously developed a rapidly growing retrobulbar swelling causing severe exophthalamos of the left eye. Antibiotic and steroid therapy were ineffective and the animal was killed. At post-mortem the retrobulbar fossa was found filled with bone fragments and fibrous tissue containing numerous yellowish-white granules 1-5 mm diam. An intense pyrogranulomatous response was demonstrated histogically, and hyphae and chlamydospores typical of Monosporium apiospermum [Petriellidium boydii] were seen. Aspergillus fumigatus, presumed to be a contaminant, was isolated in culture, but conidiophores suggestive of P. boydii were also seen, and a diagnosis of opportunistic maduromycosis following injury was made.