Vegans, by definition think it's wrong to exploit animals. Not to be confused with people following a pant based diet for other reasons, these are not vegans, they often incorrectly use the label but that doesn't change what it means to be vegan which is to be against exploiting animals.
Would a vegan, someone who has already made the decision that animal exploitation is wrong, exploit an animal to save another is not a question a vegan needs to think about or non vegans need to know what vegans think about.
The only question that matters is, If you don't have to exploit animals, would you? Vegans have answered that question, the answer is no we would not.