Place the tuna, splash of water, and catnip into a blender.
Cover, and puree until smooth and a bit fluffy.
Beat the egg white until stiff.
Fold together half of the egg white and the pureed tuna together, then fold in the second half.
Spoon the mix into a resealable plastic bag.
Cut a small hole in the corner of the bag.
Squeeze ½ inch kisses onto foil-lined baking sheets.
Bake for 15-20 minutes at 350*.
Store in an airtight container.