many medical researches require use of nonhuman animals. tis especially true 4 early researches when there are many unknowns n dangers 2 the test subjects. those cannot be done on human for safety reasons.
there are research guidelines on treatment of research animals. in general, a minimum number of animals should be used. they should be treated humanely n kept in a healthy environment. at the end, once the experiments are completed, they should be either retired or terminated in a painless manner.