Livestock keepers in West Africa rely largely on treating their cattle with drugs to protect them from trypanosomosis, but resistance to these drugs has emerged in many areas. This film outlines good practices for improving the use of drugs and slowing the emergence of resistance. These practices, which are based on Rational Drug Use, an approach from human health now adapted for animal care, are clearly explained so that veterinary workers and farmers can treat animals safely. Rational Drug Use can be combined with other methods that reduce the numbers of tsetse flies to further slow the spread of resistance to trypanocidal medicines. This is one of three films telling the story of the current state of the war against a disease that is so deadly and widespread that farmers call it "the malaria of cattle'.