When I was 41 I took on my last dog. I’d already loved Becky-the-beagle and Ajax and Jack and Ajax again (he lived long and with most of us), but Shelby was the first companion I acquired on my own.

I think I thought I was doing it for the kids, and I know I thought I was helping out when my friend Pat’s grown son Aaron had to give up his one-year old puppy for some apartment opportunity. All of that combined to introduce me to Shelby, a half-wild shepherd/retriever mix who entered my life for 16 years.

If it were up to me I would have chosen a dog with long hair (but I came to appreciate how easy it was to clean and dry Shelby, especially since we lived creekside and she developed intestinal problems). I would have preferred a more domesticated animal (I knew she loved me but I always wondered: if she got hungry enough, would she eat me?) And I certainly wouldn’t have gone for the medical problems she soon presented; it turned out that she was allergic to just about every mote or bug that exists at sea level, and I acquired a notable amount of knowledge about dermatology, injections, and steroids while living with her.

She was attractive enough. She resembled a Rhodesian ridgeback without the ridge. Or a Doberman with reverse coloration. She was golden tan with black markings.

She looked like a hunting dog but she had the soul of a retriever. She’d go for anything (teasing her with a basketball was a riot), but she appeared to be finely and precisely bred to seek out, fetch, and selectively skin bilious-green tennis balls.

That’s right. Tennis balls. She loved them all and had a radar for the lost ones. She’d rip the leash away and dash hell-bent for a hill or gulch of ivy and sure enough, every time, return with a ball. Nothing could bring her to you faster, from wherever, than the sound and scent emitted when you popped open a new can of tennis balls.

It wasn’t a sexy skill. It wasn’t admirable. But the thing about Shelby was how good she was at her calling. She was an amazing athlete. She sure could get the ball.

I learned from her. We’d walk to the dog park on Hearst, the one over the BART system, and when we entered the double chainlink gates she was just another bitch mutt. Until I threw the ball a few times. Until Shelby got to show her speed, her leaps, her obvious, all-out, don’t-get-in-her-way technique. Then all the other dogs backed up and bowed. They made way for Shelby at the water bowl.