Forty dog-faced fruit bats (Cynopterus brachyotis) were administered 1 drop of 1% ivermectin topically as part of a routine physical exam and deworming program, and 11 developed sudden generalized paresis. Six of the bats recovered within 24–48 hr, and the remaining 5 were presented recumbent and weak to the University of Florida Veterinary Medical Teaching Hospital. Ivermectin toxicosis was suspected, and the admitted bats died or were euthanatized within 3–5 days of the development of clinical signs despite supportive care. Three of the dead bats had renal tubular necrosis.