Akita dogs grow fastest when they are around 5 to 10 months old. They are basically formed around 11 months old and will not undergo any major changes. Therefore, the dog should be given additional supplements before 11 months old. Nutrition. Akita dogs are medium-sized dogs, so they eat more than small dogs, but don’t feed them too much, otherwise the dog will become too fat and easily increase the burden on the bones and joints.