Your dog is a member of the family, and like any other member of the family if they are not feeling their best you want to make sure that you take them to a vet to see what the issue is. While a dog can’t exactly tell you that they are sick, you can tell. It isn’t just that they may moan and whimper a bit here and there if there is an issue that is bothering them, they may also act listless, and spend most of their time sleeping.