What is wrong with people trying to control animals sexual reproduction. Animals been fucking since the age of time however, when humans came along it became a problem. Now I know some may say there are health risk but, there are health risk with humans as well. Getting a dog pregnant won't automatically kill her. Just like getting a human pregnant won't automatically kill her. However, the real issue here is that his post is insane.
You mention that she is not your dog. So, do you really think your friend not going to realize his dog is pregnant? Secondly, why would you risk going to jail or losing a friend because he found out you had sex or mated his dog? Thirdly, I don't think you should try putting dog sperm in your dick. I mean there could be health risk not to mention where are you even going to get it from while it is fresh.
Now I can add more reasons but I think these are good enough.