If you do decide to change his or her name it will probably be best to use the new name for something specific to begin with... like when you are going to feed or play with him or her... and then continue using it more and more, whilst using the other old name with increasing rarity.
I have found the following resource, which could help you find a new name...
Favorite Puppy Names – Your resource for thousands of dog names in categories like movies, TV, and foreign language. Also find free puppy pictures, tips on naming your dog, and free dog ecards.
