8 month old Ella

I got Ella at 5 weeks old from a puppy mill. I started her obedience training at 6 weeks, positive reinforcement with clicker style training. She is now 8 months old and as of recent she has turned into a terror.

She gets a tremendous amount of exercise, goes to doggie daycare 3 days a week, get to run (off leash) in the park an hour on the days she stays home. She is really a great dog and is potty trained well, does what she is told (most of the time), however, in the past few weeks she has started walking around the house eating and chewing on anything she can find. I walked outside last night for 10 minutes, when I came back inside she had eaten a hole in my couch.

Any tips on how to turn this around?