Anthrax bacteria react to drought and high temperatures by making more spores, which animals then ingest or inhale. An infected animal can die within hours and the bacteria can spread quickly, decimating herds.
Veterinarians have told producers to watch for sudden deaths in their herds and vaccinate quickly to stop the infection spreading.
Over 100 animals have died from anthrax infection on ranches in Colorado and Texas in the past fortnight, and veterinarians have warned that numbers could increase further if the drought continues.
