There is a difference when you're using the pound as a shopping list. If you can flip through the pages, take stock on the best ones, determine the one you want, and flip back to the page with that pet on it then you're using it as a shopping list.
On the other hand, if you have to refresh a bunch of times to get a good idea of what is in there, it is still difficult to determine the best pet or the pet you want without knowing 100% all the pets that are in the pound. And then even if you determine what pet you want, getting it to show up again requires more work.
So obviously making the pound have multiple pages would cater to people looking for specific pets in the pound rather than new players and players who aren't as descriminant about what pets they get.
It's obvious the only reason anyone would want multiple pages is so they can use them to pick and choose your pets that they recieve from the pound.
It's for exactly this reason it wont get added to the game and it is fine as it is.