To which animals do VA rules apply?

The correct response is that VA (Veterans Affairs) rules apply specifically to live vertebrates. This includes all species of animals that possess a backbone, such as mammals, birds, reptiles, amphibians, and fish. These regulations are designed to ensure the humane treatment of vertebrate animals used in research, teaching, and testing.

The inclusion of live vertebrates under VA rules reflects the recognition of their capacity for pain and suffering, which has been well-documented and acknowledged within ethical frameworks governing animal research. As a result, these regulations are more stringent regarding the care, housing, and treatment of vertebrate species.

Other categories, such as fish and amphibians, are indeed vertebrates; however, the distinction made in this question emphasizes that the rules are specifically framed for live vertebrates collectively rather than individually by category. Conversely, live invertebrates, though they are part of research and scientific inquiry, do not fall under the same set of regulations due to differences in regulatory recognition of pain and welfare. Thus, the focus squarely on live vertebrates aligns with the intent of the VA regulations to provide protective measures for animals considered capable of experiencing distress.