Can I miss puppies?

So, none of the puppies are missable, but there are some that can seem missable. By that I mean, the areas in which they are become harder to access later in the game. These puppies are:

• 55-57, and 73-81 (3 sets) - They are in Monstro. You can get back to Monstro, but you may have to fly through that area a few times before he is there.
• 43-45 - In the clocktower at Neverland. If you wait too far in the game, you'll have to fight the optional boss to be able to access the area again
• 49-54 - At the Cave of Wonders in Agrabah. Same as above, an optional boss will need to be defeated if you wait until later in the game.