When it comes to dietary needs, every dog has individual needs, regardless of age. So there's no one easy answer to the question of soft food versus hard food. Both types of food can provide your dog with the nutrition your dog needs—providing you are feeding your dog a quality dog food that is nutritionally balanced and complete.
If your dog has very specific health concerns, such as aging joints or weight issues, consult with your vet for more information about what type of food best addresses your dog's needs.
That said, there are a few reasons why you may want to consider switching your senior dog to soft food.
As your dog gets older, his teeth may become more sensitive, which can make chewing kibble more difficult and even uncomfortable for him. Switching to a soft food will help to alleviate his oral discomfort when eating.
Remember, if your dog is experiencing serious pain at mealtime from a condition like tooth decay or gingivitis, switching to soft food certainly won't remedy the problem. So make sure you talk to your vet about oral care and dental treatment.
Digestion begins in the mouth with saliva, so if your dog has a tendency to bolt down his meals, he may not be adequately chewing the food or adding enough saliva to it. Soft food can aid with digestion because it's more easily broken down and therefore more easily digested.
Whether you choose dry food, soft food, or a mix of both, ask your vet before making any transition. And when it's time to switch your dog's food, you must do it slowly—even if it's the same brand and flavor—to help prevent stomach upset and/or diarrhea.