I think that pets which are in the Graveyard, Show Rooms or Shops shouldn't show up on the High Scores list. Newer players or those just beginning training shouldn't have to get past dead/Show Room pets to make the list. If I stuff my Kayoki in my Show Room and disappear for a few months (which I do from time to time), others shouldn't have to still compete against my scores if they want to be on the list. If BillyBob hit the lottery and went on a cruise around the world, sadly forgetting Sinbad and crew (sorry), his now-dead Creatu would have to be resurrected to once again dominate the charts.
If you want your pet's scores to appear, you should have to take care of it: it should be on your profile. That's all.
Thanks for lookin'. :)