50 moves sounds like a lot, but is barely enough in this level.
Only one Pet can be on the board at a time, so you need to bring down 8 individual Pets.
Try to be efficient with every move and don't be tempted to go for the 2x blocks on the right unless you're near the end and can see that you have enough moves.
Make matches from the bottom up and try to make the columns slide to the left.
Use the solid obstacles on the board to knock Pets off the top of their column so they fall down and are rescued.