After 18 months of no visitors because of COVID-19, Angus now believes we should never have any visitors. (Laurie Hertzel • Star Tribune/The Minnesota Star Tribune)

I'm on our screen porch, watching with a little thrill of joy as Angus and Rosie snuffle with Kristin, each trying to get more pets and scratches from her than the other. Tails are wagging so fast they are rotating.

This is something of a miracle — just a few weeks ago, Angus was lunging and barking at Kristin when she tried to enter our yard.

Let me back up.

Kristin was one of two dog-sitters who cared for Angus and Rosie in 2019 when my husband and I went on vacation. For about 10 days that September, she lived in our house. The dogs loved her.

But not long afterward, COVID hit and we all went on lockdown. We had no visitors in our house for 15 months — almost half of Angus' life.

By the time things opened up again in May, Angus had forgotten Kristin.

Actually, he had forgotten just about everyone he'd ever known — or maybe he had simply decided that going more than a year without company meant we should never have company again. In any case, anyone who tried to visit us was met with ferocious barks and frightening lunges.

This was enormously depressing. If nobody can enter our house, how can we entertain guests? And if the dog- sitter can't come inside, how can we ever leave town?

All of the socialization that we had done for the two years before COVID was pretty much out the window. Angus needed to start over at the beginning. And because he is both dog-reactive and human-reactive, his beginning is more basic than most.

Fortunately, Kristin is extremely patient. And fortunately, I got a lot of good advice from various experts, including from our vet, folks at the dog rescue and an animal behaviorist. We now have a plan. If your dog is having trouble with post-COVID guests, maybe our plan will be useful for you.

1. First, we muzzle him. Even though he's never bitten anyone, never even tried to bite anyone, we want everyone to be safe and feel safe.

2. Next, find neutral ground. The sidewalk in front of your house is probably not neutral to your dog. (It's not for Angus.) Try across the street, or in a nearby park.

3. Keep a good distance and go slow. Figure out how far your dog needs to be from your guest, and start there. I put Angus on a leash and we walked parallel to Kristin about 30 feet away and slowly narrowed the gap over multiple visits.

4. Ask your guest to ignore your dog. This is unnatural; dog lovers have a hard time with this. But not only should they ignore him, if he does react to them, they should whirl around and turn their back on him.

5. Decide who will go first. Angus, we discovered, doesn't like being followed, so when we reached a part of the sidewalk where we had to go single-file, Kristin went first. Remember that it's easier for a dog to enter a space where a stranger is than it is for a stranger to enter the space where a dog is. When Kristin followed us into the yard, Angus barked at her. But when she went into the yard first and we followed, all was peaceful.

6. Let the dog set the timetable. Do not rush things.

Over time, Angus began to relax. Kristin came by once or twice a week, and by the third week, she and Angus and I could walk side by side. She even took the leash for a while.

By the fourth week, Angus had no problem with her coming into the yard, going onto our back porch and heading into the house.

And by the fifth week, he was clamoring to be petted. (Rosie, who is older and nonreactive, remembered Kristin immediately.)

Now it's time to start on Visitor No. 2.

One important point our behaviorist made is this: Dogs don't generalize. Just because Angus has accepted Kristin doesn't mean he'll now accept everyone. We need to add people to Angus' social circle one at a time, starting at 30 feet away each time.

I realize this is asking a lot of our friends. I realize not everyone is going to want to do this. And I am acutely aware that when winter comes it's going to be tougher.

But the wider we can make Angus' circle of friends, the more relaxed he'll be around new people. And maybe I'll finally be able to go on vacation again.

Laurie Hertzel is not a dog expert, just a dog lover. She has chronicled the life of her reactive rescue dog, Angus, since he was a puppy. Read all of the stories at startribune.com/puppy.