Brandy's Mom

We just returned from a week long vacation. While away we boarded Brandy, our 1 yr old Boxer, with our dog trainer. Since picking her up 2 days ago she has been acting weird. She usually always wants to go outside and when inside wants to play. Since picking her up she seems to want to stay in and curl up on the sofa. She actually burrows under the back cushion. She has also tried to dig thru the seat cushions. Her appetite has decreased and a couple times beagn panting for no apparent reason, not exertion or heat. Anyone have any ideas? She is my first dog and I'm very concerned. Thanks for any help.