Which oil/flour should I use for dog treats?

I prefer while wheat flour for humans and dog treats. Lots more natural B vitamins and less processed. Try this oil free recipe:
2 C whole wheat flour
1 T baking powder
1 C unsalted natural peanut butter
1 C skim milk
Mix all together. Can roll out into shapes (1/4" thick) or just drop onto greased cookie sheets. bake 20 min or until light brown. May need to refrigerate them depending on how fast you use them-they will go bad of left sitting out in hot weather
The dogs love them and they are healthy and nutritious. I don't know of any wheat free recipes if the dog has an allergy. Most dogs don't but if they do, may need to purchase special snacks

Since grapes/raisins are toxic to dogs, I would refrain from using grapeseed oil.

Wheat, when it has had the daylights processed out of it, is converted to a form not fit for consumption, thus making it allergenic. Dogs don't naturally seek out and eat grains; the grains and fiber they would get would be from the stomach contents of the herbivores they eat in the wild.

So if you're going to used flour, use unbleached, whole grain wheat, bulgar, quinoa, barley. I would also use olive oil - even though it's a bit pricey, even the corn/vegetable/canola oils you see in the markets have been processed and lightened in color to make them more appealing, and are far down the line in nutrition.

You could also add eggs for elasticity. They are a powerhouse of nutrients and most dogs love them.

Good luck!

Some dogs can be allergic to wheat or even certain oils. I would recommend to use light oil. In Real Food for Dogs by Arden Moore, her veterinary approved recipes usually called for vegetable oil and wheat flour.