New gene editing technologies present numerous opportunities for improving the living conditions of animals in general, and of farm and laboratory animals in particular. However, using these biotechnologies to ameliorate the lives of farm or laboratory animals remains prima facie problematic, being very often a form of techno-fix. In this article, we propose an approach for analyzing the possible applications of gene-editing technologies for bettering the lives of farm and lab animals based on the animal ethics principle of respect for telos. According to this principle, what matters from a moral standpoint is not so much the final balance between suffering and pleasure, but rather the degree of freedom to pursue one’s nature. Contrary to what one might think, an ethic based on respect for telos does not entail the prohibition of modifying animals through biotechnologies such as gene editing, since it does not require an essentialist view of species. In this sense, it would be possible to modify the nature of an animal as long as a principle of “welfare conservation” is adopted – that is, as long as we do not introduce into the telos of an animal new behavioral demands that are hard to fulfill or traits that make existing behavioral demands harder to satisfy.
