Your 13 month old terrier takes a new toy and shakes it until the squeak dies. Then they work a hole in the seam and lay the stuffing out across the rug. It takes 4 minutes.
Owners ask whether this is aggression. It is not. It is the most terrier thing your dog will ever do, and there is a sensible way to live with it.
What the shaking is
Terriers were bred to find small quick animals and deal with them alone, without waiting to be told. Grab, shake and dispatch is the end of that sequence, and a toy is the nearest available stand-in.
Adolescence turns the volume up. The sequence gets faster and more committed. Around the onset of the stage, dogs also respond less to the cues of the person who raised them. That responsiveness returns later.
None of it is directed at you, and none of it predicts a dog who is dangerous to people. A dog killing a toy on the rug is a dog having a very good time.
Channel it instead of banning it
Keep 2 or 3 toys your dog is allowed to destroy, and let them. Cheap soft toys, cardboard boxes, or a towel with treats rolled inside it, used where you can supervise.
Rotate the rest. Keep 4 or 5 good toys in a cupboard and bring 1 out at a time, so none of them goes stale.
Play tug with rules. You start it, you play for 60 seconds, you ask for the toy, and you pay the release. The rules are what make it useful.
Play structured fetch: 1 throw, 1 retrieve, your dog gives it up, and you decide when the next throw happens. Stop before your dog is frantic rather than after.
Finish every game by putting the toy away and giving your dog a chew on a mat. Relaxation is trained as a behaviour in its own right, in short repeatable sets below your dog's threshold.
Add nose work on the days the weather is against you. A searching dog finishes settled, where a shaking dog finishes revved.
Teach a swap, not a removal
Do not pull things out of your dog's mouth. A hand that takes things is a hand worth guarding against.
Offer a second identical toy, or 3 pieces of something good, and pay the moment your dog lets go. Then hand the toy straight back.
Practise the swap when your dog has something they care about mildly, before you need it for something they care about a lot.
Reward-based training is associated with higher reported responsiveness and fewer reported problem behaviours. A dog who trusts the swap is the one who gives up the sock later.
Where it can tip into guarding
Destroying a toy is not guarding. Guarding is about what your approach predicts, and it looks different. Watch for these.
Stiffening, freezing, or eating faster as you walk past.
A hard stare over the top of the toy, a lifted lip, or a low growl.
Moving the toy away from people and settling somewhere they can watch the room.
Taking the toy to a corner or under furniture and going quiet when anybody approaches.
If you are seeing those, stop the swap practice and read about food bowl and object guarding first. The handling is about distance and trades, not about proving you can take things.
Punishment-based approaches are associated with fear, avoidance and defensive aggression, and a growl that has been told off is a warning you no longer get. Never correct a dog for growling over an object.
Behaviour change is built from management plus reinforcement together. Here the management is picking up the contested item when you are not there to supervise.
Safety note
Swallowed stuffing, squeakers, plastic eyes and rope strands cause blockages, which are a veterinary emergency. Supervise every destroyable toy and bin the pieces as they come off. Call your veterinary practice if your dog has swallowed part of one, is vomiting, straining, or off their food. Get help now if your dog has growled at, snapped at or bitten a person over a toy. The same applies if there are children in the house and your dog stiffens over objects. Book a veterinary examination too. Sudden behaviour change warrants one, and pain frequently presents as a change in behaviour rather than as obvious lameness. A child is never the person who practises a swap with the dog.
If this is one of several adolescent things going on at once, the Assessment will sort which to work on first. It is free, takes about 3 minutes, and asks for no email address.
Today's version, in one line: 60 seconds of tug you start and stop, then a paid swap, then the toy goes in the cupboard.