A 5-year-old castrated male American Shorthair cat presented with lethargy and anorexia after accidentally knocking over a bottle of topical minoxidil and spilling it onto its body. Physical examination revealed rapid shallow breathing, pale mucous membranes, hypothermia, tachycardia, and hypotension. Thoracic radiography revealed mild pulmonary infiltration and pleural effusion. Despite conservative treatment, including oxygen therapy, and intravenous fluid, furosemide, and dopamine administration, the patient showed no improvement. After two sessions of intermittent hemodialysis, the cat’s respiratory pattern and overall condition gradually improved; normal body temperature and blood pressure were achieved. The cat recovered fully and was discharged on the 11th day of hospitalization. This is the first report on the use of hemodialysis in the treatment of a cat with minoxidil toxicosis.