my 2 year old lab x is very sad.. i dont know how to cheer him up

Question
Hi, just recently my dog has been very sad recently - he is a 2 year old male lab x border collie. we have raised him since he was just 4 weeks old and in the past 2 years he has been very energetic and lively. he loves playing with balls and loves going on walks. That was up until recently, in da past to weeks he expresses no interest in playing with any toys, balls or us! neither does he want to go walking. he just hides behind furniture in which ever room i go to, he will always stay close by but will hide. i have tried to do everything to cheer him up, we have even bought him a new puppy to try and get him to be the energetic dog that he is. its very heartbreaking for me to see him sad and the fact.

i cant think of anything that is making him change behavior inside and outside of the house! he loves playing with other dogs, he puppies he plays with in the local park, he is showing very little interest in them too. please help me because i truely have no idea what to do to cheer him up.

I will answer all questions about canine behavior. It would be helpful if you could provide dog's name, age, sex, breed and how long you have owned the dog. In addition, I would like to know how long the problem has been occurring, what you have tried to solve the problem(s) and what were the results. Please be specific. The more information you provide me - the better equipped I will be to offer sound, helpful advice! Thank you.
p.s. If your question pertains to house training, play-biting, teaching sit and down, or jumping up, please visit my website for free instructions. If your question pertains to fear or aggression, please visit my website - before you post- and read "problem behavior solutions". Please let me know if you have visited my site and and read the free information. Site addy is http://www.howsbentley.com
Please do not mark questions as private. MY MOTIVATION FOR VOLUNTEERING ON THIS PUBLIC FORUM IS TO HELP MANY PEOPLE AT ONCE.

Answer
Hi Asha, Has the weather changed, any household changes...? Have you taken him to the vet to find out if he is in pain for some reason? If not, please do so right away. Did this begin when you got the new pup? If so that could be your answer, if not there is another reason. Do not humanize him, what I mean is don't put your human feelings for him on to him. Don't coddle him and say poor boy, instead build his confidence. Try building up his security, socialize him, take him for walks at the heel with you daily, at least, to exercise his mind and body. Give him special time that is confidence building rather than pity. But do check with your vet to be sure that he is not suffering from some problem. Leave me some feedback and an update to let me know how you are doing. Thanks. Regards, Susan