You seem to have a very specific idea of what a "better dog" is.
I'm not sure why you say that. The traits I listed for a dog class were just what's already in the dog write-up in the Monster Manual: Good Fort and Ref Saves; Listen, Spot, Swim, and Wilderness Lore skills; the Trip quasi-feat. I then extrapolated a bit, thinking of Feats appropriate for a dog -- real police dogs disarm suspects with a bite to the arm, for instance -- and real Skills appropriate for a dog.
That's what I meant by a "better dog". I like the idea of an Owl Sorcerer or a Wolf Druid, but I also like the idea of a Faithful Hound who isn't anything more than a "better dog".
Not all dogs are particularly tough, or especially good trackers, or any better in a fight than "run up and bite it", etc.
Well, right. I only need a dog class for a high-level PC dog, an epic dog, a Lassie or Rin-Tin-Tin.
To get exactly what you want, you'd have to essentially devise a separate character class for every breed of dog you wish to include.
Or I can give them a wide enough list of Class Skills and Bonus Feats that they can just choose the appropriate ones.