Vampire bat control by systemic treatment of livestock with an anticoagulant.

The blood of beef cattle given single doses (1 milligram per kilogram of body weight) of diphenadione (2-diphenylacetyl-1,3-indandione) became toxic to vampire bats (Desmodus rotundus) and remained toxic for 3 days without harming the cattle. Cattle at three ranches in Mexico treated with single intraruminal injections of diphenadione experienced a reduction in vampire bat bites of 93 percent. Bioassays of milk and liver from cattle treated orally with diphenadione in the laboratory indicated that there were no residue problems.