**Garlic and Onions can be toxic to dogs. Typically the problem is with large quantities not "seasoning portions". You should seek the advice of your veterinarian to find out if garlic used in minimal flavoring amounts is appropriate for your pet. If in doubt, leave the ingredient out.
From the very friendly folks at RecipeGoldmine.com
Recipe for dog treats with beef broth, egg, honey, white, oat or rye flour, wheat germ, cracked wheat, bran, oatmeal.
A good wheat-free recipe uses cornmeal, flax seed, rolled oats, baking powder and canned tuna
Homemade dog treats are fun to make and healthier than many of the store-bought versions.