If you have a pet with it's original name ,A Horse for example, or managed to name your pet with 2 names in KR BB_Ehanced UI it seems clicking on the name in the pets bar will revert the name to the first letter. If you hit enter this makes the change permanent. If you simply click in it again and hit exit instead this reverts it back to it's current name. In the example of A Horse, click once gives you A, hitting exit reverts it back to A Horse. This can be done as long as you haven't hit enter.