I was downstairs with Gryffindog in the park just in front of our house today when, out of nowhere, a jubilant yellow lab came lolloping toward us. I’m always extra vigilant when Gryff meets a new dog for the first time; you never know when one or the other won’t be friendly. But I quickly dropped my guard as this dog exuded pure joy with every move. She was just so happy to be alive. I couldn’t help but notice, though, that a patch had been shorn off the fur on the middle-right of her body. It took me a second longer to realize that the dog was running on three legs. And only then did I see that the wound at the shoulder of the missing leg was fairly fresh. Finally (keeping in mind that all happened in the space of about seven seconds), I recognized the dog as one of Gryffin’s friends. One we hadn’t seen all summer.

Tessa’s owner and I shared “Welcome back”s and “How was your summer”s before I ventured to ask what had happened. She’d been hit by a car. It was touch and go for a while. The vets had to take the leg. But she was bouncing back more quickly than expected, defying all odds and expectations.

What's the secret behind her swift recovery? I asked...