Why does research involving dogs and nonhuman primates create additional ethical debate?

The use of dogs and nonhuman primates in scientific research creates significant ethical debate primarily due to their high cognitive abilities and emotional complexity. Because these animals exhibit sophisticated mental processes, social behaviors, and evidence of consciousness, many argue that they possess a moral standing that necessitates greater protection from harm.123

Ethical concerns center on the following factors:

• Sentience and Consciousness: Research suggests that primates and other social species possess at least a rudimentary form of consciousness. This raises fundamental questions about the moral status of these beings and whether it is ethically permissible to subject them to pain, distress, or death for human benefit.231
• Cognitive and Emotional Complexity: Unlike some other animal models, dogs and primates demonstrate complex social interactions and problem-solving capabilities. Their capacity for suffering and their ability to form bonds—often with human caretakers—intensify the moral scrutiny regarding their treatment in laboratory settings.214
• The Problem of Consent: A central ethical issue is that these animals cannot consent to participate in experiments, which challenges the moral justification for using them as subjects.1

While supporters argue that physiological similarities to humans make these animals critical for advancing medical knowledge, the ethical consensus emphasizes the importance of minimizing suffering and adhering to the "three Rs" (replacement, reduction, and refinement) to protect their welfare.1