Well, I posted this a while back...

Aside from that, well there are TONS really... if you like horses there are the Black Stallion series by Walter Farley, the Silver Brumby series by Elyne Mitchell, War Horse is the sad story about Joey, a horse involved in the first world war, written by Micheal Morpurgo, the Flicka series by Mary O'Hara, The Brumby series by Mary Elwyn Patchett revolves around a boy in Australia and his beloved horse Brumby. Walt Morey has written Sandy And The Popstar (about a popstar who runs away, tired of the pressure and meets Sandy, a puma that is being hunted) and Runaway Stallion which is about Jeff who finds a wild horse and vefriends him, but becomes devastated when the real owner turns up. Jack London's two books White Fang and Call Of The Wild are also great. If you're looking for more books from the animal's perspective (besides Thor, which I posted about in the above link) there is Watership Down by Richard Adams (bout rabbits) and The Cold Moons by Aeron clement (about badgers, very similar to Watership Down). The Incredible Journey by Sheila Burnford is really touching and great.

...I could go on forever!