Preheat oven to 350°F. Line a baking sheet with parchment paper.

Wash and dry the strawberries and blueberries; finely chop the strawberries and leave the blueberries whole.

In a medium bowl, whisk the whole wheat flour to break up any lumps.

Add the peanut butter to the flour and mix until the mixture looks crumbly.

Stir in the chopped strawberries and whole blueberries until lightly coated with the flour mixture.

Add the egg and mix until combined; the dough will be thick.

Add the water gradually, a little at a time, stirring until a soft, workable dough forms that holds together without crumbling.

Lightly flour a clean surface and roll the dough to about 1/2 inch thickness.

Cut the dough into small shapes using a knife or cookie cutter and place the pieces on the prepared baking sheet.

Bake for 25–30 minutes, until the treats are firm and lightly golden on the edges.

Remove from the oven and let the treats cool completely on a wire rack before serving to your dog.