Dan Coleman's children, Ray, 5, and Zia, 3, snuggle with Claudius, who just celebrated his 15th Christmas with the family.

At some point within the last decade, my wife and I acquired a collar adorned with tiny Christmas trees and began a tradition of putting it on our dog, Claudius, when we bring the Christmas stuff up from the basement. I’m surprised we continue to find it, more surprised Claude is still here to wear it.

This year, as my kids and I buckle it around his neck, I explain that this will be his 15th Christmas.

It’s difficult to make them understand how old he is. I tell them Claude has been with their mom and me since before we were married, or even lived in Lawrence. I tell my son, who just turned 5, that his dog is three times his age, and just a day younger than their human cousin, who started high school this year. I don’t dare delve into the concept of “dog years,” but still let them know Claude is 98 by that tally, decades older than their grandmas, and probably older than any person they have ever known.

“Old Faithful: Dogs of a Certain Age” is a new book at the Lawrence Public Library in which Toronto photographer Pete Thorne has published his portraits of elderly dogs in all their “patchy, scruffy, jowly, and devoted glory,” along with brief biographies of each provided by their owners.

They don’t quite get it, but anyone can tell he is ancient just from his frosty face. I did a double take last month when I saw a dog who looks just like him on the cover of a new book at the library, “Old Faithful: Dogs of a Certain Age,” in which Toronto photographer Pete Thorne has published his striking portraits of elderly dogs in all their “patchy, scruffy, jowly, and devoted glory,” along with brief biographies of each provided by their owners.

Perhaps they, like me, wonder how their pups passed them up. Cats get all the credit for being mystics, but dogs warp time. How can mine be the same animal I held up with just one hand by his bare belly, pink as a piglet’s, until he got sick all over the steering wheel on our memorable drive home from the shelter 14 years ago? How can a little black mutt, so thoroughly green that day, now be the oldest and wisest member of our family?

Like many a grumpy old man, Claude has lost his filter. He pushes open doors, grabs food from the kids’ hands, shoves his way past us all. He is half blind, mostly deaf, batty in the brain and sleeps for hours in the same spot. We clap our hands to call him because he can’t hear our voices. I watch for breath in the rise and fall of his chest first thing when I wake up.

And still each morning, we walk. He leads with his nose in the predawn dark, defiant of sidewalk and road, senseless to passing cars as he focuses on all that’s left for him to appreciate — the calling cards of other neighborhood dogs, cats and maybe the occasional scent of a fox or raccoon. I watch him absently. Long ago I forgot he wasn’t just another part of my own body, although I’m reminded one recent morning when we stray too far afield, and one of his hind legs, arthritic and unstable from an old injury, fails him such that I almost have to carry him home.

Dan Coleman's children, Ray, 5, and Zia, 3, snuggle with Claudius, who just celebrated his 15th Christmas with the family.

I wonder if it is finally time to make the awful decision my wife and I have felt looming all year. I let my worries slip in a passing conversation with Miss Linda, familiar to so many in town from her storytimes here at the library. You can’t read stories to children for years and not end up knowing something about animals, seasons, and the passage of time. Her comment eases my mind: “Don’t worry. You’ll know when. He will tell you.”

Then she adds a dose of horse sense for this dog person: “And maybe just don’t walk him so far.”

Oh yeah. Claude may have outgrown me when I wasn’t looking, but I still hold the leash in this relationship. I was this dog’s dad from the time I cleaned up that first little mess in the car, long before I ever had kids. Parenting doesn’t require children, after all; only others we care for and protect — our pets, our partners, our players, our employees, and eventually, even our own moms and dads.

This year I’ve found myself helping my own mom through a pair of joint replacement surgeries, dropping off new clothes at her rehabilitation facility (“They dress so nice here!” she pleads), riding up and down with her in the elevator to the cafeteria and raising a ruckus in her room with my kids to rival any college dorm party. “My son and daughter seem a little like my mom and dad these days, except they are still afraid of me,” she tells a nurse.

As we had hoped, Claude celebrates his 15th Christmas, and my daughter Zia, just turned 3, accompanies us on our walk that morning. Bundled up in her jacket and hat, she’s now big enough to hold Claude’s leash. She watches him roll on the grass, then poop.

“It looks like a Slinky!” she cries.

I pull out my handkerchief and wipe her runny nose. It’s hard to believe, but someday this one will outgrow me, too.

— Dan Coleman is secretary on the board of Dads of Douglas County. He is a part-time stay-at-home dad, but in his other life he is a librarian at the Lawrence Public Library, where he selects children’s and parenting books for the Children’s Room. He can be reached at danielfcoleman@yahoo.com.