Companionship - It may be that they don’t understand everything you say to them, but dogs do respond to tone of voice and know that being affectionate with their owner is part of the deal. Not like cats that only know cupboard love and only come around when they want something. Dogs often have that ‘I love you’ look in their eyes whereas cats will watch you doing something and you just know they are thinking ‘I would do it like that’ or if you are painting they are saying ‘You missed a bit’.
It is surely the number one reason that people own dogs, the friendship aspect and it is true that the dog is mans’s best friend. You can talk to them and pet them and send them running off after a stick or a ball. In the evening because they are a social animal they will want to have some contact with you. Some owners let the dogs be a complete part of the family with access to the sofa too. I don’t allow my dog on the sofa and certainly not allowed to lie on the bed. Again some dog owners like to let the dog sleep in the same room, personally I think that is going a step too far.
Fitness - Having a dog of a reasonable size means that they need some exercise. You have to take them out walkies, they will insist. Mostly it is so that they can do their business but also so that they can do the sniffing and exploring. While you are walking the dog you are also getting out into the fresh air too. Walking is good for you and gets the blood moving around your body and the air in and out of your lungs. Cardiovascular training by dog walking. You can even do some running with the dog, the dog will keep up with you and run alongside at your heel. I know some people will also take out the bicycle and have the dog get more exercise. It really depends on the size of the dog. I know some people cheat when they have a huge dog by driving the car and the dog is well exercised. For that it has to be a big dog and on roads or tracks where there is no other traffic. It might be good for the dog but for the owner it is cheating.
Health - There is evidence that people with dogs are healthier overall. Partly because of the extra fitness by getting the fresh air and walks, but also because dogs have germs and things that are around you too and you build up an immunity. Despite being as clean as you can be with having a dog in the house, there will be extra bacteria that will be beneficial in a roundabout sort of way. Dogs will lick you, some dogs are more likely than others to do that but overall it is good for you. Despite what you might think when the dog comes and gives you a big smackerooney all over your face when you weren’t expecting it. A sloppy wet tongue, a cold nose and dog breath in your face could actually be good for you, despite your protests.