In a large bowl, mix together the drained canned salmon (flaked with a fork), the reserved salmon liquid, mashed sweet potato, egg, and olive oil. Stir until the mixture is smooth and fully combined.

Slowly incorporate the oat flour and brown rice flour into the wet mixture. Keep stirring until the dough comes together firm yet pliable. If it feels too sticky, sprinkle in a bit more oat flour until it reaches the right consistency.

Lightly dust your work surface with oat flour. Roll the dough out to about ¼ inch thickness. Cut into small shapes or squares using a cookie cutter or knife, sized appropriately for your dog. Arrange the treats on a baking sheet lined with parchment paper.

Preheat the oven to 350°F (175°C). Bake the treats for around 25 minutes, until they turn golden brown and feel firm. Remove them from the oven and let them cool completely before offering them to your dog.