In early November, shortly before his third birthday, Angus apparently decided he was growing up too fast. Suddenly, we were back in the puppy years.

So now I wake up in the morning and follow a trail of shredded Kleenex from the upstairs bathroom, down the stairs and into the living room. Kleenex! He hasn't been shredding things — or diving into wastebaskets — for two years. But now, suddenly, he is.

Or I find dish towels dragged from the kitchen, holes gnawed in their middles, or throw pillows hauled halfway up the stairs.

One morning I came down to a cascade of feathers. In the middle of the night, someone (I'm looking at you, Angus) chewed open the corner of a couch cushion and turned the feathery innards into confetti.

Every day, it seems, brings a new odd behavior. On walks, Angus does fine on the paved pathways but the minute we step off onto the grass or the snow, he reverts to puppyhood, leaping and jumping, grabbing the leash in his mouth and playing energetic tug.

I have to say, it's endearing, and I often let him prance and pull as much as he likes.

Other behaviors are not charming, such as his distressing new habit of lunging at moving vehicles. I haven't figured this one out yet — it's not every walk, it's not every car. It seems completely random, but it happens often enough that I know it's turning into a habit that I need to curtail.

Why would a three-year-old dog suddenly do this? He has never paid the slightest bit of attention to cars before.

Of course with Angus, the question is always "why" for everything.

That playful puppy behavior — the Kleenex, the feathers, playing tug across the grass — might come from a new happiness and confidence that his medication has given him. It's been just about four months since we started him on Trazodone, and we finally have the dosage and timing of it pretty well figured out.

He takes his first pill with breakfast, which comes at the ungodly hour of 5:30 a.m. He's ravenous, and he wolfs the pill down with his kibble.

The midafternoon pill is a little trickier.

We started off wrapping the pill in a corner of a tortilla, which we slathered in butter, and that worked great until, suddenly, it didn't. One day he saw me pulling out the tortillas, and he ran out of the room.

We moved on to rolling the pill in peanut butter, which worked for a while, and then enrobing it in Velveeta cheese. The cheese worked for a long time. But now if I pick up the box of Velveeta he runs out of the room.

We have hidden the pill in a small bowl of dog treats (worked once), hidden it in a dollop of canned pumpkin (worked once) concealed it in a meatball (worked once, and he was delighted) and slathered it in spaghetti sauce (never worked).

A few times I resorted to stuffing the pill down his throat, but Angus is good with the gag reflex and that was not easy. Plus the last thing you want to do with a skittish dog is stuff something down his throat.

For now, we are hiding the pill in a chicken-flavored commercial product created for administering pills. So far, it's working, but Angus turns the experience into a huge drama: He rolls it around in his mouth, spits it out, sniffs it, rolls it around again, nibbles at it, spits it out. Sometimes he walks away and I have to pick it up and trot after him.

I'm a little worried about 15 more years of trying to trick Angus into taking his pills — I'm not sure there are 15 years' worth of new and delicious food products I can hide them in.

But we persevere. Because, frankly, 15 more years of Angus playing like a puppy does not sound like a bad thing at all. (As long as he leaves the couch cushions alone.)

Laurie Hertzel is the senior editor for books at the Star Tribune. She has been writing about her rescue dog, Angus, regularly since he was about four months old. Read past columns at startribune.com/puppy.