Is my dog ill or stressed?

I own a year-old Pembroke welsh corgi named Stubbs. Lately he's been running around from one family member to another, panting, barking, and making jerky motions. He's had all his shots and hasn't been bitten by any animals. He's my first dog and I am not exactly experienced with them. Do you (the reader) think he has a condition, or is this withdrawal from the family's usual routine (since it is summer vacation)?