Editor’s note: This is the first in a series of three columns about children and pets.

I believe it was the day after our 15-year-old border collie-Lab mix died that my two children (ages 8 and 5 at the time) began to lobby for a new dog.

Even though we didn’t miss her daily accidents and tumbleweeds of fur and old-age stink, the house wasn’t the same without our sweet Sydney. We needed something furry and licky and waggy to love on us again, and of all pets, only a dog is capable of giving that particular ego-boost.

About four months later, my husband pointed out an advertisement in the pets section of the paper; my eyes subsequently oozed from their sockets as I gazed on the three most adorable creatures ever made in the world. They were five-week-old border collie pups, and I knew I had to have one, preferably that day.

I have included the photograph that ran in the paper, as proof that it wasn’t a fair fight. No dog-lover in her right mind would have turned from those puppies. My husband and I drove out to the breeder the next day and picked out a pup from the litter (only three were left), and I took the little guy home to surprise the kids when they got home from school.

It was just like an after-school special, the way we all took to the energetic puppy, who we collectively named Harry (in honor of our favorite wizard, Harry Potter). But we soon began to see what it might mean to have a purebred border collie as a pet.

See, the breed was trained a long, long time ago to herd sheep. It’s hard-wired in their DNA to be intense, athletic and hard-working. In lieu of actual sheep, they will try to herd anything that moves.

Harry took a liking to our feet. Every morning, by way of greeting, he would attack our moving feet with his little needle teeth. The kids were so traumatized by this that they carried bowls of dog treats downstairs in the mornings to distract him from his smelly prey. He also liked brooms and vacuums and scooters and bikes and small children running through the backyard.

But we didn’t truly care about Harry’s neuroses, for we already knew him to be the missing piece of our family puzzle. Then came the day that he started vomiting up his food. After a couple of days of periodic vomiting, I grew concerned, but his listlessness was the most alarming symptom. Based on what I knew about border collies, I surmised that a listless border collie pup was a sick one.

I took him to the vet, who told me that his kidneys weren’t functioning properly and recommended that I take him to the specialty veterinarian to have some tests done. We all left poor limp Harry at this vet for testing, not quite believing we’d never see him again. The vet called us the next day to tell us that his nine-week-old kidneys were indeed failing (no reason could be determined without an autopsy), and gently suggested that we put him down.

It was one of the saddest days of my life. And yes, I cried for a long while after that phone call. But telling my husband and children, and watching them mourn poor Harry, was much more painful than my own grief.

With Sydney’s death, an explanation was easier to give: she was old, she had a good life, we’ll get a puppy. But how do you explain the death of the puppy? My mind was aswirl with existential notions about the unfairness of life, but children need something a bit more uplifting, more nourishing, in times of crisis.

My kids fell asleep that night with tear-stained faces, following some blubbery words I spoke about pets and how they teach us about unconditional love.

We learned, alright. But we hadn’t learned our lesson about border collies. We picked up Harry’s brother – the last of the litter – from the breeder the following week.

To be continued…

Diann Ducharme is the author of The Outer Banks House and is a wife, mother of three children and owner of one border collie. You can find her at http://www.diannducharme.com where, she blogs about the writing life.