If there were no squirrels in the world, Angus would be perfect.

Well, that’s not entirely true. We would have to get rid of rabbits and chipmunks, too. And cats. And, I guess, most other small mammals. But really, I’d be happy just to eliminate squirrels.

From the beginning, Angus has done pretty well on walks, but he has never been perfect. Squirrels have always been a problem. Also, when he was quite small, he went through a spell when he wanted to play tug with his leash. This was followed by a spell when he liked to stop suddenly right in front of me, perhaps to see if I would trip over him and fall, and then a spell when he dashed behind me, maybe to see if he could wrench my arm out of its socket.

Then he went back to playing tug.

So this summer we signed up for leash training.

The class met in a grassy area of Como Park. There were five other dogs, and Angus, predictably, barked at them as though he wanted to kill them and then a few minutes later initiated play with a corgi and a goldendoodle.

The instructor explained the basics of polite leash-walking, which are pretty simple: Imagine a line that extends from your hip straight out to the side. If the dog crosses that imaginary line, stop him. Pause to let the magnitude of the dog’s sin sink into his little doggie brain. Whirl in front of him and deploy the “back!” command.

Then walk on.

When he breaks the line again, stop, pause and whirl again.

And again.

And again.

Do this until the dog learns or all joy is sucked out of walks forever.

Angus caught on quickly. (“He’s really smart,” the teacher told me, sounding somehow ominous. “Really smart.”)

So for a week we practiced the basics, and then we moved on to the second class: how to handle distractions. Such as squirrels.

Here’s what I wrote on my Facebook page that evening:

“Tonight, in a two-block stretch, there were these distractions: a tennis court full of dogs racing around and wrestling like they were at a dog park; a loud barky dog in a yard who rushed the fence at us; a small dog walking briskly on a leash; a cat sitting in the middle of the sidewalk as though he owned the place; and, when we turned the corner, a fat rabbit. We tried deploying the ‘anticipate’ procedure, the ‘emergency U-turn’ and the ‘pivot’ and in the end just ended up dragging a screaming Angus down the street.”

But over time, there has been improvement. As with all animal training, it requires diligence on the part of the human, which hardly seems fair, but there you go. You can’t leave it up to the dog.

If, on walks, I let my mind drift, Angus speeds up, just a little, and without thinking I keep up with him and then he speeds up a little more and I keep up with him and pretty soon there we are, racing down the sidewalk.

Stop, pause, whirl.

This morning Angus was perfect on the walk. (This happens less than half the time.) I distracted him from the squirrels and chipmunks, we walked past people and dogs nicely, we even stopped and let a group of mallards waddle slowly across our path. Angus just sat quietly and cocked those ears.

And then, a half-block from home, a young man surprised us. He was wearing headphones, checking his phone, and carrying a pizza box, and he came suddenly around a corner and almost banged into us.

I am not sure which technique I deployed — not distraction, and there was no U-turn, so it was probably a pivot. Whatever it was, it worked beautifully. There was one sharp bark out of Angus, and then we cut a wide berth around the oblivious pizza guy and continued smoothly on our way home. Success! Though I am pretty sure this would not have been the case had the pizza guy been a chipmunk or a rabbit or a squirrel.

Laurie Hertzel is the senior editor for books at the Star Tribune. She is not a dog expert, just a dog-lover, chronicling her puppy’s first year on these pages.

Coming Sept. 29: In sickness and in health. Follow Angus’s adventures at www.startribune.com/puppy