Abstract Drawing on the features of “practical philosophy” described by Toulmin ( 1990 ), a “practical” ethic for animals would be rooted in knowledge of how people affect animals, and would provide guidance on the diverse ethical concerns that arise. Human activities affect animals in four broad ways: (1) keeping animals, for example, on farms and as companions, (2) causing intentional harm to animals, for example through slaughter and hunting, (3) causing direct but unintended harm to animals, for example by (...) cropping practices and vehicle collisions, and (4) harming animals indirectly by disturbing life-sustaining processes and balances of nature, for example by habitat destruction and climate change. The four types of activities raise different ethical concerns including suffering, injury, deprivation, and death (of individuals), decline of populations, disruption of ecological systems containing animals, and extinction of species. They also vary in features relevant to moral evaluation and decision-making; these include the number of animals affected, the duration of the effects, the likelihood of irreversible effects, and the degree to which the effects can be controlled. In some cases human actions can also provide benefits to animals such as shelter and health care. Four mid-level principles are proposed to make a plausible fit to the features of the four types of human activities and to address the major ethical concerns that arise. The principles are: (1) to provide good lives for the animals in our care, (2) to treat suffering with compassion, (3) to be mindful of unseen harm, and (4) to protect the life-sustaining processes and balances of nature. This “practical” approach arguably makes a better fit to the complex, real-life problems of animal ethics than the single foundational principles that have dominated much recent animal ethics philosophy. Content Type Journal Article Category Articles Pages 1-26 DOI 10.1007/s10806-011-9353-z Authors David Fraser, Animal Welfare Program, University of British Columbia, 2357 Main Mall, Vancouver, V6T 1Z4 Canada Journal Journal of Agricultural and Environmental Ethics Online ISSN 1573-322X Print ISSN 1187-7863. (shrink)