This study systematically traces the philosophical discourse on animal status from ancient Western civilizations through the Enlightenment, with particular emphasis on analyzing the three dominant contemporary animal ethics theories of utilitarianism, animal rights theory, and the differentiated treatment model, alongside the core tenets of the “3R principles” (Replacement, Reduction, Refinement) and the “ Five Freedoms”. It reveals substantial divergences among philosophical frameworks in defining animals ’ moral status, evaluating the legitimacy of experimentation, and assessing institutional feasibility. Utilitarianism prioritizes cost-benefit analysis to maximize aggregate welfare, while animal rights theory advocates for the absolute prohibition of instrumental animal use. In contrast, the differentiated treatment model proposes a balanced approach that reconciles ethical obligations with scientific advancement. Empirical evidence demonstrates that implementation of the 3R principles has effectively reduced the scale of laboratory animal utilization, while the Five Freedoms framework has substantially mitigated animal suffering in experimental contexts. We further address emerging ethical challenges posed by novel technologies, arguing that future advancements in laboratory animal welfare must harmonize scientific progress with ethical imperatives. This requires formal recognition of animals’ sentient capacities and human moral responsibilities, supported by iterative improvements in alternative technologies and optimized experimental protocols. By integrating meta-ethical analyses with practical regulatory frameworks, this research establishes a normative foundation for resolving tensions between biomedical innovation and interspecies justice.