Preheat oven to 350°

Bring a pot of water to a boil. Add spinach and allow to boil for 5 minutes.

Drain spinach, reserving 1/4 cup of the water.

Place boiled spinach into food processor and puree.

In a large mixing bowl, combine all ingredients.

Knead dough until a soft dough forms with the consistency of Play Doh.

Press dough out to approximately 1/4 inch thickness. Cut shapes with a cookie cutter or top of a glass.

Arrange on a cookie sheet lined with parchment paper.

Bake for 20 minutes.

Remove from cookie sheet and allow to cool completely before giving them to your dog.

Store in an airtight container at room temperature for one week. To keep longer, store in refrigerator.