When the patent for a painkiller expired in 1993, cheap generic versions were introduced to the market across the Indian subcontinent and were quickly adopted by livestock farmers. While this benefited livestock agriculture, it unintentionally led to a massive decline in vulture populations that fed on cattle carrion that contained residue of the painkiller. Because vultures are obligatory scavengers who crowd out other mammalian scavengers such as dogs and rats, their decline was predicted to lead to an increase in infectious diseases, in particular rabies from animal bites by feral dogs, and potentially higher levels of morbidity and mortality. Using district-level data on all-cause death rates, we compare districts of high to low habitat suitability for the affected vulture species, and find that human death rates increased, on average, by three percent following the vulture die-offs.
