Thunder,just turned 3, is very similar.We have to call him several times for his walk.He would sleep all day and night,in fact,he takes himself to bed around 9pm and we don't see him again til morning.He growls if you try to move him!! When he does get going he will run around,but nothing hyper,and after a short play,he is done for the next few days!.He would never be any good at pulling anything or running races.But bless him,he is no trouble at all and we really don't know we 've got him!.Thats why I love him so much!