Pets & Animals
Is he eating a new brand of food?.. or may be the reason it's just because he's eating so fast. Try to divide his meal in two or three parts and watch him to see his behavior. And another thing that you should do is wet a little bit his food, sometimes it works.
He is quite ancient - almost 15 and his digestive system is not what it was - I give him one particular brand of food which is high in cereals with dry dog food and steer clear of those with lots of gravy/jelly. Maybe your suggestion that the food is to dry is the cause of the problem. I will see if adding some water helps.