There is a way to do this. I'll put it in steps for you.
-Any kind of cooked meat (No FISH)
-Dyes (whatever color)
- Make a wolf that loves you. (Must be NAMED.)
- Make your wolf sit.
- Make your friend come to the wolf and give it rotten flesh.
- Make your friend give the wolf a different color leash with dyes.
- Make your friend give the wolf some cooked meat. (No FISH.)
- Both you and your friend have to log out at the SAME time.
- Re-join and your friend should have ownership.
This is a 1.8.1 glitch. I am not sure if it will be here for the future updates. I discovered this on my own and have tested it multiple times. Basically you are tricking the game into thinking your friend is the owner, by feeding it and changing it's color. When you log-off the game reloads and your wolf is now coded to love whoever cared for it last.
You are so welcome and I hope you enjoyed reading my reply :D. Have a good time with your friends dog!
-Water_Mint. An all time Mine craft player.