Someone mentioned on another thread that dogs don't "need" these things, obviously they haven't dealt with the power of anal gland secretions
I give my 11lb mini dachshund 1/2 tsp garlic & brewers yeast, 1/2 tsp coconut oil and 1/2 tsp unsweetened low fat coconut flakes in the morning with 1/4 cup kibble. In the evening I give him 1 teaspoon pumpkin with kibble. I add 1 tsp yogurt 3 times a week. You should adjust accordingly but make sure that you don't give too much coconut flakes because it could cause constipation! Add some water to soak the coconut flakes if you're not giving him coconut oil.
May I ask what kind of food you are feeding him? I'm not trying to start another silly food debate here, but my dog had a problem with loose poop (hence the anal glands) and he got much much better when he started on a grain-free diet.