If you have a dog for many years, you would notice that there are some changes in his behaviour you might not understand. You should know that the majority of them are the result of a decline in his functioning. If you ask a doctor you will find that through years their awareness, ability to learn and hearing would deteriorate, and this might lead to many behaviour changes. Therefore, you would notice that he might be sleepy during the day, even if he used to have a lot energy, and play around before, and he finds difficult to sleep at night. But, you should pay attention to these symptoms, because some of them might not be the result of his old age, but of a health condition. Therefore, if you notice that your dog is eating grass or poop, you should call a veterinary and ask them Why do dogs eat poop?, because there are multiple causes which might lead to this. Here are the main behaviour changes your dog might experience as the years pass.
Your dog would be more talkative
You would notice that your dog might be more talkative as the years pass, and this is not a sign that he becomes more conversational, but this is a symptom of a disorientation caused by a cognitive dysfunction. Other causes might be that he experiences pains or he is becoming deaf, some of the dogs even suffer from arthritis. You should take him to the vet to have him examined, because you have to identify the medical condition, which might lead to it. In case the doctor states that there is no physical cause, you should offer him more attention, and train him to be quiet by offering him treats when he is quiet.
Waking or restless at night
As they age, dogs experience vision or hearing loss, and this impacts their sleep. Also, he might be triggered to overreact to noises he would not be disturbed of before, and this might have as result the fact that he is not resting well in the nights.
Going potty inside the house
Also, you might notice that your dog is taking his elimination habits indoors, and you should not get upset, if he is old, because this does not mean that he becomes disobedient. This is one of the changes dogs suffer through years, so you should know that inappropriate elimination could be caused by less control over his bladder and bowels, a decrease in mobility, frequent urge to eliminate, and even brain tumours. Therefore, you should consider talking with a vet about this issue, because you have to find if he has a health issue.
Your dog eats poop
You might have not noticed this action until recently, and you consider it something that might come with age, but you should not make this mistake, because this is one of their natural instincts. Before being domesticated, dogs were scavengers, and they used to eat whatever they could find, so this habit of him is not a change thanks to its age.