As your dog grows there are certain habits that are bound to change just like humans and some new habits are developed during the entire process of adulting.
This is something you will notice as he will give you clear indications that he is not full and wants more food. Even after you have fed him with food he’ll be around his bowl or lick it after he’s eaten the entire food this means he is not full and wants more food. Once you understand all the signs he is trying to give increase the quantity of food you are giving to him but that shouldn’t be increased too much at once this should be done gradually until once he’s eaten everything from the bowl he walks away from it indicating he is full.
As dogs grow old they tend to become lazy and usually prefer to lay down most of the times. Young dogs are more active than the older ones the later doesn’t like being indulged in any physical activity. The younger dogs are very enthusiastic and playful they like being around everyone whereas this thing is missing in the older dogs they prefer being at one place.
This might seem a bit weird but this is true when they are in deep sleep especially in nights they do snore loud enough for everyone to notice. I remember the first time my dog snored I was looking for who is it that is snoring so loud that I am unable to sleep I checked all the rooms at my home and later when I went near my dog I realised it was him. That was literally too surprising because I never knew that even dogs snore that too like humans.