Pet Rescue Saga Level 517
Target: Save 2 pets
The main thing to remember in this level is not to open the mesh on your locked blocks until they are down lower in the game.
The highest you can let one lock is nine blocks up from the bottom row (the small rectangular box with a little downward arrow and number tell you how many rows you are from the bottom)
Once the bottom row is in view, then you can use the paint and bring the pets down.
The level can be completed without even unlocking the blocks if your pets have slid to the left and are below the locked ones.