our Jack, a recently rescued chocolate lab, does that when left in the car. We were so spoiled with our Maddy, a yellow lab, and her "sister," Lexie who died in July, Jack came to us in September. No matter how long they would be in the car, they never did anything wrong. Jack ate a porterhouse steak (yes, with Maddy, we could leave food on the floor and she would not take it), then he chewed the collar off my jacket, then through a Lands End canvas bag, and finally, he took one bite of our digital camera. We learned--now, if we leave him in the car, he gets a muzzle. We feel badly but it's protection for all. I was thrilled with my DH who did not beat the boy or even scream at him for any of the above. In the house, he's learned not to chew though when we're at work, he is crated. Never is he crated if we're home nor is he crated at night; he sleeps with us--me, DH, and Maddy (we need a larger bed). Soon, hopefully, we won't need to crate him at all. And, btw, they are never in the car for longer than 1/2 an hour. Maddy would rather be waiting in the car than left at home.