Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.

Wash and dry the strawberries and blueberries, then chop the strawberries into small pieces.

In a medium bowl, combine the whole wheat flour and peanut butter and mix until crumbly.

Add the chopped strawberries and whole blueberries and gently fold them into the mixture.

Add the egg and stir until the mixture starts to come together.

Add the water gradually, stirring until a soft, workable dough forms.

Lightly flour a clean surface, place the dough on it, and roll or pat the dough to about 1/2 inch thickness.

Cut the dough into desired shapes using cookie cutters or a knife.

Arrange the cut treats on the prepared baking sheet, spacing them slightly apart.

Bake for 25 to 30 minutes, or until firm and lightly golden around the edges.

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