Hi, I had the same problem with Webster at 9 weeks (now 10 weeks), I took him to the vet and at first he said that Webster is too small to have anal glands but I insited he checked it out and "viola"! His anal glands were infected, he drained it and gave him a antibiotics shot. After only one day he was up and about and even more full of live!! This site helped me so much and you can realy take them to heart, they know what they are talking about and all their support is just wonderfull!!
Please don't take to long to take him to the Vet he really needs to be checked out, I you had him dewormed this is the only other thing that can be wrong with him.
Good luck.
Linda & Webster