Experimentation and research are very important aspects that have preserved the lives of many animals, since without them, we wouldn't know how to treat animals when they fall sick or understand the best ways to ensure their proper development.
If an animal is likely to die during an experiment and then we use that knowledge to better our society, then it's acceptable to conduct experiments on it, provided there's a probability that such an experiment can heal the animal or be useful in treating another animal in the near future.
You are even talking about animals, it is on record that some researchers used humans forcefully for their experiments. The stories of how African slaves were brutally used for experiments by developed nations bring so much sorrow and pain to my heart. These slaves were dissected alive for research purposes. Others were used for drug tests and were made to suffer terrible effects.