I can understand the thought process behind wanting to let someone else experience bestiality who may not have the chance otherwise, but I think that you'll find yourself feeling connected to the dog and not wanting to share. Even if you do still want to, there's a lot to think about. You probably won't catch an STD from the dog, but you could get anything that the other person leaves behind. How would you know that the person you're allowing to be with your dog is trustworthy? Do you already know people who you plan to let fuck your future dog? I won't tell you to do it or not, but there's a lot that you should consider, and your feelings could very quickly change on the matter after you have her.