We woke up to a commotion in the middle of the night, coming from the dog bed.

At first, we thought maybe one of our three dogs was having a bad dream. Or that the two smaller ones were having a little dust-up. But it quickly became clear that this was something different. It was Darcy, our oldest and largest dog, convulsing.

Darcy, an Australian cattle dog mix we rescued more than 12 years ago, had always seemed unbreakable.

We adopted her from the Humane Society in 2011 when she was roughly 2. Since then, we never took her to the vet for anything other than annual checkups, vaccinations and other preventative care. In old age, she had gone 90% deaf and maybe 50% blind. But she otherwise seemed to have made it through life without debilitating health conditions or illnesses.

On top of that, Darcy was quite possibly the sweetest dog on Earth. We called her a "love pig," because she was greedy for affection.

But this December, we noticed she started putting herself to bed earlier. A couple of times, we had a fair amount of trouble waking her up from what seemed like extraordinarily deep slumbers. We're now think she was having small seizures. Then, she had a very big one. She was sleeping on a chair in front of the fireplace when she began to thrash uncontrollably. Within seconds, her mouth was yawning open and snapping violently shut. She must of bitten a gum or a cheek, because there was blood.

That's when we understood it was probably time.

As dog owners, we have been lucky to go so long without a loss. We'd never, as a family, had to put a beloved pet to sleep.

The timing, as it turned out, was at least somewhat fortuitous. Our adult daughter, who no longer lives nearby, had fretted for years about the prospect of not being able to be present at the end of one of our dog's lives. She just happened to be at home when Darcy had her big seizure. Our daughter was able to stick around to head to the animal hospital with us.

We found ourselves wrestling — as so many dog owners eventually do — with the fleeting, nagging, heart-wrenching doubts about whether it was indeed time to let her go.

We wrestled with those doubts even after the veterinary nurse brought that big jar of mini-chocolates into the room and pointed out that "every dog should get to try them." Even after Darcy snacked on one, then two, then three, then another four more after that. Especially after Darcy surprised us by climbing to her feet, despite the sedative flowing through her bloodstream, so she could beg for yet more chocolate. As we gave her another, then another, laughing through tears at her piggishness, before she finally collapsed into our daughter's arms and settled back into the blanket on the floor.

Not until Darcy started seizing again while drifting off to sleep (though mercifully less violently than before, due to the medication) did we feel 100% certain that we were doing the right thing by letting her go now.

My daughter stroked her back, my wife stroked her head, I stroked her paw. We said as many soothing words as we could.

And so it was that in the final moments before her passing, Darcy was able to enjoy — one last time — two of the things she'd grown to love most during her full, healthy, wonderful life: gleefully eating stuff she wasn't supposed to, and blissfully feeling showered with our affection.

We will miss her terribly.