Welcome to the Pet Rescue Community
Do you need help with your game? Ask the Community for help.
This isn't a game I play a lot but if you're looking for help then head to YouTube. There's always a lot of videos, some with and some without boosters and here you can always pick up a strategy and see what you need to do for those extra 2 pets.
https://www.youtube.com/results?search_query=1421+pet+rescue