Do teenage dogs- like between 15 mos and 2 yrs- usually go through another phase of destroying things? Greta was doing really well, such that after her spay in March we gave her access to the living room and kitchen only while at work. Last week and the week before she chewed on the corner of some trim, which we hit with Bitter Apple spray. My security camera just let me know that she apparently destroyed a decorative couch cushion this morning. Heading home at lunch to clean up and check on her...

I will put the x-pen back up to prevent further mischief, but I wish I knew whether this was a 'teenager' phase or if it's that she's not getting enough exercise and OB.

I did flip our schedule last week so that we're walking 2 miles in the mornings and training in the evening in lieu of the opposite... could that have been it? She seemed tired when I left a few hours ago!

Dogs will be dogs when opportunity strikes. I would limit the freedom, or leave some interactive toys out. Myself, I would limit the freedom.
Sometimes they just know no one is around to stop them lol.
She is still young, there will be plenty of time for freedom. Harry is 8 months now, and he only gets access to the kitchen at night. I am lucky to have a pup with zero counter interest. And I am a light sleeper so can hear when he wanders and catch him if he is getting to prowly. Is she crated at night?

With great probability she will calm down with age. Nonetheless, she needs to learn some house strict ruules. now. Agree fully with Becky about limiting the freedom. Once she's grasped the first rules fully, you can still give her (gradually) more freedom.

My pits, when they were puppies destroyed at night everything which could bve trated as a toy, Mattresses which they could use to play tug of war together, everything we left thoughtlessly lying on the ground, like slippers etc. etc.
A friend of mine, who breeds Bernese Mountain Dogs, has a puppy who discovered socks, which the husband had left in his shoes. She was occupied and didn't supervise him consistently enough. The dog swalled them! She saw it in the last moment and could catch one of them, but the other one was already in his stomack. They neede a big and expensive surgery surgery and could easily have lost their puppie.
She has decades of experience, even though unpredictable things can happen in a blink of an eye. So limit the freedom absolutely and don't leave her anything which could be misunderstood as a toy.Our dogs since then never get any toys, unless we ourselves ar playing with the.m. Exception: a Kong, when they are alone in their kennel or crate, just as a passtime.

I appreciate the good suggestions as always. I might have included too much info, though, and my question got lost.

Is there a recognized period of development in the 15-24 month age range where they are testing their limits more than 'usual'? For instance I've read about fear periods, teething, etc.

Thanks

Fear period, yes, currently hitting the 8 month stage here. But I believe testing boundaries lasts til maturity, for my breed 3-5 years, lol.
Comes with the hormones. Which even after spay and neuter, can linger for up to 6 months according to my vet.

GSDs average about 18 months old when they "start" to mature.

How they are handled up to that point will have a big influence on how far they may push.

As to destroying things, that can slow down when their adult teeth come in at aprox 6 months old.

Young dogs do only what they can get away with and that should be our responsibility to control that.

If you can't keep a constant eye on a pup or young dog then it's freedom MUST be limited as Becky said above.

It's more about management issues then actual "training".

A cautionary tale.

When we went to bed, one night years ago, when Titan was about seven months old, we thought a toy would keep him occupied if he got antsy in the night. Seemed to work every night.

That next particular morning, I walked into the kitchen to brew my morning cup of coffee, and lo and behold, Titan had decided to methodically eat the kitchen table and chairs set.

Now, I'm not talking about a few gnaw marks, I am talking about eating the rungs off of three of the four maple chairs, and trying to eat one of the feet off the maple table. It was shocking the damage he inflicted on perfectly innocent furniture. Overnight.

The kitchen set was for all intents and purposes really and truly destroyed. And because he greeted me, wagging his tail and all excited to see me, there was little I could do to show him the error of his ways. After all, I didn't catch him in the act. I wasn't happy.

Since that time, there have been lots of nylabones or however you spell that, all over the place for gnawing. And no more furniture has been devoured. AND, far more attention by me to even the possibility of any of the dogs snacking on furniture or anything else that I prefer they do not eat. I made an assumption on the behavior of Titan the puppy, and I was wrong. Shame on me.

That noted, it seems to me that after six or seven months it is easier to train out the more undesirable behaviors. But anticipation of things that can go wrong goes a ways to help form training boundaries. And training is really never ending.

What floored me was the nonchalance my bride exhibited when confronted by the destruction. I expected a negative outburst and a litany of rules but no. It was a lesson to me.

Titan is taking his afternoon siesta by the fireplace. Yup, he's still here, and a faithful companion.

Mike said

"What floored me was the nonchalance my bride exhibited when confronted by the destruction. I expected a negative outburst and a litany of rules but no. It was a lesson to me".

HMMMM! Did your bride get a new kitchen set out of this?

Hey, hey! There's not always a sneaky calculation behind it when wimmins understand a dog!!!

Toni ate the bed one day when we were On Vacation and the dog sitter left her in the house- she had been fine the whole week before, but at that time she felt she needed to kill whatever monster was in the bed. And she did a right thorough job of it too.

None of my dogs really went through any rebellion phase or anything like that. They learned their places in the pack and were content with it.