“Merlin has the brain of an 18-year-old dog,” said the neurologist, pointing to our 18-MONTH-old pup’s MRI image on the screen. He honed in on the large streaks and patches of white in Merlin’s brain, then showed us a healthy dog’s brain, which was mostly blackish-gray with minimal traces of white.

“His brain is shrinking.”

My wife cried. I blurted out, louder than I intended in the small exam room, “What? Really? You’re kidding me? No.” The doctor wasn’t kidding. And though we suspected there might be something wrong with Merlin’s brain, we had expected a tumor or lesions – an ailment that could be treated with radiation or steroids, not one out of a science fiction movie.

Our sensitive gem of a dog that we’d adopted and raised from a pup had a rare central nervous disorder, NCL, seen once a year at the vet hospital. It had no cure or method to slow it down. And no amount of money could extend his life or our time together. Merlin had a month or two left to live.

My wife had noticed changes in Merlin back in October. A shy dog always, he now seemed more withdrawn at times and fearful. He now shook his head after stressful situations, like a tick. I thought they were hiccups. My wife knew it was more. But Merlin ate his food and everything else seemed fine. Life went on, but my wife watched him closely.

December and the holidays rolled around and I got very sick. So did Merlin, though we didn’t know it. We thought the changes we noticed were behavior related. He wouldn’t go on walks anymore. Every blowing leaf, passing car, barking dog and random sound caused him to park himself on the sidewalk or roll over into the gutter. During one walk, as the sun set, my wife had to pick him up and carry him back to the car. Darkness spooked him.

On a late afternoon in January, with the low winter light glowing gold in those the moments when afternoon flips to evening, I heard Merlin barking and growling in the bedroom. Not normal. Turning the light on, I spotted him backed into a corner beside the nightstand barking and growling at nothing. He snarled and whipped his head from side to side, hitting the wall, as if trying to shake the grasp of a phantom.

I coaxed him out of the bedroom and got him to stop for few minutes when I spoke to him or fed him a treat or dinner. But it continued, on and off, for a couple more hours. Normal behavior and normal dog for a few minutes, followed by the head shaking.

At the vet the next morning, we showed her video of Merlin and explained his behavior over the last month. This isn’t normal, she said bluntly, and yet had no idea what it was. She recommended seeing a behaviorist first, then possibly a neurologist. We should have skipped right to the neurologist.

During our rapid “discovery period” of Merlin’s illness, my wife sensed Merlin was having vision problems. So, with the behaviorist a distant option, I made an appointment with an eye specialist. Across the valley, I drove, through a monsoon and rain-filled freeway cluttered with blowing trash and the shattered remains of Christmas trees someone didn’t secure to their truck, to discover Merlin was going blind.

But not because his eyes were bad, or not reacting to different colored lights and other tests that I never knew existed for a dog, but because the signals from his eyes weren’t reaching his brain. His optic nerve ignored the information, which is a central nervous system disorder, and not the news I expected or wanted.

The vet explained in detail, but my mind traveled somewhere else at that moment – to the realization a tidal wave of grief was rolling my way and there was no running or hiding from it.

The vet’s advice: Get the “first available appointment” with a neurologist.

Several days later, we dropped Merlin off for an MRI and spinal tap and waited for the news. We knew it was bad when they called and said they performed the MRI but not the spinal tap and the doctor needed to see us later that day. We knew what the MRI images would reveal without seeing them – an abrupt change to our lives, a shock to our hearts, and doom and gloom.

My wife loves dogs. She feeds them, walks them, and gives them more attention than I get from her. Yes, jealousy. And they depend on her and love her in return. It’s something to see, this bond. And my teenage daughter mirrors my wife in her love of the pups.

Now if owning dogs has opened my eyes to anything, it’s why we don’t allow euthanasia for humans in most states. Who wants to make that decision? It’s horrible and gut-wrenching with dogs. I can’t imagine what it would be like with a human. How long do you wait to do it? What’s the best timing? What’s best for you? How much suffering will everyone endure during the process of deciding?

You hope and pray you’re doing the right thing. And then you live with the choice you made and the memory of the last moments. Forever.

We made the decision to euthanize Merlin. We didn’t want to see him suffer the long seizures, or swing his head into another wall or piece of furniture. Or growl at us, or bite unintentionally. He’d already started not to recognize us. And we didn’t want to him to live in our memories that way.

I remember each dog I’ve taken to the vet for the their last visit. Mocha, our chocolate lab, age 14. It took two shots to end her life. She retrieved anything you threw, was a strong hunting dog, and slept next to my wife’s pregnant stomach at night. Harley, age 15, an all-black, low-key chow mix who was there when we brought our daughter home from the hospital after she was born, and who shared many of her childhood years. Then there was Luna, our magical yellow lab, age 8, cancer, who could read my wife’s mind and who was the most balanced and lovable of our dogs.

I live with the memories of these endings.

With Merlin, I held it together pretty well and compartmentalized the grief while I could. My daughter and wife, well, reality crushed them. Grief and love for Merlin teeter-tottered their emotions while I watched from a distance waiting to carry out my duty at the vet.

Merlin lived like an alpha wolf his last week. We fed him every great food we could think of. My wife cooked him a steak and gave him piles of chicken chunks in his dinner. He enjoyed peanut butter bones several times a day. And he snacked on his favorite jerky treats whenever he liked. A king’s life, one might say. I surprised him with a full yogurt, not just the remains of mine. One night he hopped up and ate scrambled eggs from a plate on the kitchen table. Manners no longer required, my friend. Go to town.

Life was good, life was fun in those last moments together. But they went fast.

It’s a strange feeling not to be able to swallow. It happened on the way to the vet and I thought I was going to have a panic attack, the emotions of the situation bubbling over. Our sweet little dog. The coolest looking dog we’ve ever had. His end coming way too soon.

I don’t feel like going through the details of the last hour of Merlin’s life at the vet. They were caring and gave us time to say goodbye. The moment I’ll never forget is when they gave Merlin a sedative to make him drowsy and he jumped and placed his front paws on my lap and I helped him up. I spent about 15 minutes with him curled up there, sleeping, as a petted him in the silence of the darkened room, saying goodbye, wondering what it was about this dog and the moments we shared that touched me so deeply. I’ll never know or understand. He just did. And that’s enough for me.

While I was on IVs and asleep, Merlin found a comfortable spot next to me.