My parents have a 7 year old beagle who as of recent, has figured out how to paw open the sliding glass door to the point where she can nose it open the rest of the way to get outside when no one is home.They don't want to lock the door because they are afraid she will hurt herself by keeping on trying to paw it open..she already has, and has a swollen foot. They have tried putting chairs and things in front of it, but she works her way around them. She has never had any separation anxiety issues before. Any suggestions?