it sounds like he would be happy lying around all day. some dogs are like that, i have a dog who is 10 and she would just prefer to be lazy. when you finish work as long as you still exercise him he will be ok.

If you don't already have one, consider buying a KONG. Most pet supply stores carry them. The Kong can be STUFFED with a wide assortment of goodies... You can mix non-fat yogurt with a spoon of peanut butter or apple sauce, throw in some bits of Kibble and freeze it over night...or add bits of cut up tiny human grade beef jerky...or pretty much what ever you think your dog might enjoy that will fit in the hole of the thing. It can be frozen to last a fairly good long while too. You can give it each day or every other day. You can scatter some of his dry food or treats throughout the house for him to find, just before you leave. Be sure if you are upping the amount of food treats he gets, you count that as part of his daily food intake, so as not to plump him up! A nice walk before you leave and upon your return will be appreciated by him as well...and you may want to leave some music playing as "white noise." Be aware that this is a change, most dogs prefer ROUTINE, as do all animals. With changes, there can often times develop some challenges, such as potty accidents. Both due to the change in routine AND if no one is available to take/let him out for potty needs...he could have some accidents. You will either need to figure out a way for him to gain access to the proper spot for going potty, such as a visit from SOMEONE...a friend, relative, or dog walker...noon visit from you...or set him up for success in NOT having accidents in places you don't want to have to clean up! (with the use of baby gates..gating him in an easy to clean space with his bed, water, treats and toys.) Even the best trained dog can have accidents when change causes them stress. If it does happen, he is not trying to punish you for not being there, he's just a good old boy having some challenges himself.

Consider leaving the TV on while you are gone...the sound of voices will keep him company.