The best way to help a dog chew his food is to find ways for him to eat slower. Fast eating can be dangerous and cause serious side effects, so it's important that you break the behavior as early as possible.
Consequences of Fast Eating
Eating too fast can cause nausea and vomiting, as well as general discomfort. In addition, fast eating can worsen food aggression, as a dog might feel the need to protect his food by eating it as quickly as possible. Eating too fast can cause your dog to swallow air, which can cause gastric dilatation-volvulus, commonly known as bloat. Bloat is a life-threatening condition that often requires surgery.
Slowing Down Fido
Buy a special food bowl designed to help your dog slow his eating time. These slow feeders and puzzle bowls come with a variety of valleys, ridges and center posts that make it difficult for a dog to grab large amounts of food at once. Instead, your dog needs to eat around the obstacles, naturally slowing the eating process. For dogs who tend to gulp their food, try placing a tennis ball or rocks in the food bowl. This forces the dog to eat around these obstacles, and slows his eating. Make sure the rocks are big enough that your dog won't swallow them by accident.
Remove Sources of Stress
If you have more than one dog, it's possible the fast eater is just trying to win over his competition. For example, he might want to eat fast because your other dog tries to steal food from him, or maybe because he wants to finish up quickly and steal from his partner. You can eliminate competition between two dogs by feeding them in separate rooms or crates. Once your fast eater realizes there's no need to compete for food, he might slow down on his own.
Other Tricks You Can Try
Instead of feeding your dog two large meals a day, switch to smaller but more frequent meals spread throughout the day. A treat ball that dispenses food as it rolls around is a good way to slow eating. You can try spreading kibble over a large cookie sheet rather than using a bowl, so your dog has to pick up pieces individually rather than being able to take a large mouthful from the bowl.