Helminthosporium speciferum as the cause of dermal and nasal maduromycosis in a cow.

A 4-year-old Santa Gertrudis cow had epistaxis and loud nasal sounds associated with nasal granulomas. Multiple cutaneous granulomatous nodules were on the ears and single ones on the tail, vulva and thigh. Helminthosporium sp. was isolated from cultured lesions; two isolates from the ear and nasal mucosa were identified as H. speciferum. Tissue sections stained with hematoxylin and eosin contained rounded forms ranging from 5X5 micronM to 12X19 micronM; an indistinct hyaline wall surrounded granules and vacuoles of varying size. Occasional transverse septa were present. Periodic acid-Schiff, Gomori's Methenamine Silver and Gridley's Fungus stain treated sections contained numerous smaller pleomorphic buds and a few branching septate hyphae attached to the rounded forms. Brown pigmentation of the wall was not a consistent finding.