An enzootic of stachybotryotoxicosis was established on a dairy farm in 35-46-day-old calves due to the use of straw contaminated with Stachybotrys alternans. Studied were the epizootiology, the clinical picture, and chiefly the morphology of the disease. A characteristic clinical feature was the edema in the intermandibular space. Morphologically, there were numerous hemorrhages in the subcutaneous tissue, skeletal muscles, abomasal and intestinal mucosa, kidney cortex, and urinary bladder as well as ulcerous and erosive colitis, edematized mesenterial lymph nodes and occasionally catarrhal and necrotic stomatitis, icterus, and perirenal edema. Contrary to the gross lesion picture known there were no changes in the rumen, reticulum, and omasum which were not sufficiently developed during that period. Histologically, there were degenerative nephrosis, focal hemorrhagic glomerulonephritis (occasionally coupled with bacterial embolization and dystrophic calcification of the kidneys), granular degeneration of the liver and heart, hemorrhages and edema of the lungs, and edema, hyperemia, and thrombi in the brain.