When I saw her for the first time, I thought “hell, no.”

We are not keeping this rocketing yellow blur who is tearing around my lawn and completely out of control. Half yellow lab, half golden retriever, no sense, and no training. A six-month-old puppy with oh my god more energy than I’ve ever seen in a dog. Her mother was a field line labrador, which means energetic long-legged hunting dog, not placid slow-moving guide dog.

The kids were tiny then—a toddler and a baby. Cassie belonged to a woman in my office who was heading for a divorce and an apartment that didn’t allow dogs. Cassie spent the first six months of her puppyhood alone, stuck in a house all day while her owners worked.

She started limping last Friday.

And there we were in my back yard. My husband had the biggest grin I’ve ever seen. This rampaging animal stole the sock off the baby’s foot, right in my lap. But she did it gently, without hurting the baby. My son, nearly three, watched with wide eyes, a little afraid. But he laughed.

“This is a good dog,” said my husband.

“You are insane!” I wanted to shout, but I didn’t. He was the at-home dad then. I worked. He really wanted this dog, and the dog needed a home. I was so desperately tired, still nursing a baby who wouldn’t sleep through the night, and trying to be coherent enough to remember my co-workers’ names at work. I had said for years, we’d get a dog when the whole family was out of diapers. At this rate, I might be in them by the time the kids are out. But this dog was here now, she needed a home. Right dog, wrong time.

Another trip to the vet. Oh crap. We can’t afford this.

Cassie grew with us. I tried dog training once. She didn’t make me proud, but she did make it to age three, when she finally became an adult dog instead of an idiot. My husband trained her, which meant she obeyed him like a champ, and she obeyed me when she felt like it.

She came with us. On camping trips. To the school bus stop, every day since kindergarten. To my parents house for Christmas. Around the neighborhood for miles and miles while I pushed a jogging stroller and tried to get rid of the baby fat.  To the beach, where she loves the vast expanses of sand. To the TV room, where her favorite place in the world is on the floor with four pairs of her people’s feet. To the side of my bed after I broke my leg and was stuck in bed for a week. To the field near our house where she chased balls faster than we could throw them, until knee surgery ended her retrieving days.

Maybe she’s blown out her other knee. Damn. We really can’t afford this.

Her coat is the softest I’ve ever felt. She has a lab’s short hair, but her coat is light and fluffy like a golden retriever’s. She sheds great clouds of hair. All year round. I’ve vacuumed what seems like a metric ton of dog hair out of the house, and she’s not bald. When she shakes herself in a sunbeam, another whirlwind of it floats off into the air.

When my husband went back to school, he found Cassie to be the perfect stress relief. Better than taking up drinking, with which he was sorely tempted. When he couldn’t take another book or another paper, he took her for long late-night walks through the neighborhood, pounding out his frustrations on the pavement. When he had a late class, she waited by the door for him to come home. She still doesn’t like it when we’re not all where we belong.

It’s so quiet when she’s at the vet. The house is so empty. I’ll get her at 5:00 when her x-ray is done.

She loves anything warm. The fireplace, the back yard in the sun, a sunbeam on the carpet. Her belly freckles through her pale fur in the summer. She lies in the sun for hours, then comes inside to sprawl on the floor, and waits until she cools off enough to do it all again. When it rains, she pokes her head out the dog door with the plastic flap on her head like a roof, and surveys her world, trying to decide if the cold and wet is worth chasing a squirrel or not. Lately, mostly not. Too much bother. Maybe she finally realized she can’t catch them.

“Cassie is your dog?” says the vet. “Why don’t you come in here.” She motions me to an exam room.

Cassie was born within a few months of my daughter, that baby whose sock she stole so long ago. Which means they’ve always been the same age as the year. They both turn nine this year. While my daughter has progressed to elementary school, Cassie has grown into an old lady dog with a white face. She sleeps more now, on my floor while I work, anywhere she can, but she still rockets downstairs barking like mad for the doorbell, and wags her whole body when we come home. My favorite is when she picks up a dog toy in her mouth and barks at the same time. Not a woof, more of a mumph. She hasn’t figured out that she can’t talk with her mouth full.

“She’s under sedation, she’ll wake up in about half an hour. We x-rayed her knee, and her leg.”

My son is eleven now. He is the most attached to her. She tiptoes into his room at night and snuffles him awake. He talks to her, and he knows how to rub her ears just right to make her groan with happiness. He knows the Van Morrison song, “Brown-eyed Girl” and sings it with me when we hear it on the radio. It’s Cassie’s song. He’s old enough to take her on walks and feed her. She knows all his fifth grade problems, but she keeps her secrets.

When I started working at home a few years back, she became my office mate. It’s hard to pound away on a deadline with a snoring dog in my office. She pokes her nose under my mouse hand and flips it onto her head. She sleeps on my feet. She takes me for walks when I need them.

“Her knee is fine, but there’s a shadow on the x-ray near her ankle. We’re sending it to a radiologist to be read, but it looks like bone cancer.”

The vet is full of advice. Procedures. Tests. More sedation and x-rays and a biopsy and another sedation just to get enough information to see the veterinary oncologist. “We want you to have all the information.” But she speaks in if/then statements. If we do this, we might get that. Might. Maybe. If. At the outside, if we’re very lucky, we might get two years. She doesn’t say what we might get if we’re not lucky.

I wait in the car and cry. I call my husband on the phone. I can’t find another kleenex.

She’s an old lady dog. She loves us, and she hates the vet. She doesn’t like being groggy for hours. My husband and I talked and talked. He told me about Sid, his parent’s neighbor, who went through months of hellish cancer treatment. Just before he died, he said he wished he’d skipped the whole thing and gone fishing.

She’s groggy and tired. I have to lift up all eighty pounds of her to get her in the car.

I thought we had another three or four years. She’s so happy, so full of life. But along with not having buckets of money to spend, I can’t make the end of her life all about trips to the vet. It takes an odd kind of strength to say no. I want so badly to panic, to say yes, to put it all on the credit card. Dammit, I want her to live! But for dogs, all times are now. Every day is a good day. The vet says maybe one to three months before the pain pills she gave us won’t work any more.

How in hell are we going to tell the kids?

We told them this weekend. My son burst into tears. My daughter said, “Can we get another dog?” She’ll get it, eventually, but for now, she doesn’t. Sometimes it's a blessing to be oblivious.

It’s the questions that make my son cry all over again.

“Will she be with us for Christmas?”

“Probably not.”

“Can we take her to the beach?”

“Yes, we’re going next week, remember?”

“But then won’t that be her last trip?”

My son is learning the hard reality that people live longer than dogs.

She’s here with us, for a few more weeks or months. We don’t know how long. I can’t put it in my day planner. Some day, sooner than we want, it will be time. All we can do is wait.

Until then, she’s having good days. Sleeping in sunbeams. Walking to the bus stop. Barking with her mouth full. All times are now.