I counted, 46 / 100 of the most popular dog names end with an ē sound, and 5/10 of the most popular cat names in the UK end with an ē sound. ( 32/100 cat names from a broader but less accurate source )
Small children tend to suffix items with the ē sound, such as in the words "mommy", "daddy", "bunny", and "kitty" if this helps at all. I think that perhaps this is the orgin of the ē sound because children are allowed to name pets far more often than they're allowed to name people, but that is just a hypothesis. I also read on wikipedia that these pet names are intended to act as a diminutive to make the pet seem smaller/cuter , so that's a start.
This has been driving me crazy for weeks, can somebody please explain why ~50% of pets are named with an ē sound while only ~15% of people are named with an ē sound?