was having problems with this quest but... with some help got it done. Didn't see any really helpful forum posts or links on wiki so....
For the Sake of the Zoo.
Speak to Young Anthony in Breeze Woods.
1.Speak with Glen in Breeze Woods.
2. Defeat Orangutan Mothers in Waterfall Camp until you get a
bell with Arthur's name on it.
3. Speak to Arthur in Waterfall Camp.
4. Return to Glen.
5. Speak to Pele in Waterfall Camp.
6. Defeat Blue Clapper Dragons in Waterfall Camp.
7.You found the dog. Go back to Arthur now.
8. Go back to Young Anthony.