SassyKat's Tuna-Pops (even safe for diabetic cats)

Drain liquid from tuna packed in spring water. Freeze liquid in small ice cube trays (cocktail ice cube trays work nicely, as well as little square pill boxes available at most drug stores - only fill these half full). Give no more than 2 cubes at 1 time as a treat. Reuse your can of drained tuna by placing in it an airtight container and covering with filtered water overnight for a second batch of tuna-pop water.