We’d recommend that you first take a trip to the veterinarian to determine if your dog's finicky eating has a medical cause, Aaron. Your veterinarian will be able to diagnose and treat or rule out any medical conditions that may be causing this feeding behavior.
If there isn’t a medical diagnosis, your dog may just be a finicky eater. This can happen when pets are given people food too often, rather than their own food. It can be a challenge to change his diet when he’s been used to eating people food, but it’s important to take this step as it is much easier to provide adequate nutrition with a high-quality, commercial food.
Because your dog is under one year of age, you may want to choose a product made specifically for growing dogs. Choose a high-quality puppy food designed for your dog's size and activity level. Finicky pets may find canned food more palatable—it is often more appetizing and can be fed either alone or mixed with dry food. In addition, there are gravy-like products that can be added to dry food to increase palatability.
Just remember, it’s important to make the change from people food to dog food gradually—you’ll decrease the chances of upsetting your dog's digestive system, while helping him to accept the new food more readily. It’s best to make a slow transition over five to seven days or longer. Start by adding a very small amount of dry or canned food to the food he’s used to eating. Then over the next several days or weeks, slowly increase the amount of dog food while decreasing the amount of homemade food.
Alternatively, you may decide to continue feeding a homemade diet. If you choose to do this, it is vital that you use a recipe that has been formulated by a veterinary nutritionist and that you inform your veterinarian, who will help you monitor your dog's nutritional status.
More information about feeding your puppy can be found in the ASPCA’s Top 10 Tips for Feeding your Puppy.