I'm holding a thick wad of paper towels against my dog's hip, shushing her and patting her head. I'm fairly timid at first, worried that pressing against her burst cyst could hurt her. But instead of yelping, she just stares at me with pleading "pet me more" eyes and settles her chin against my free hand. I gently, and then more firmly, push into the spot of wet, matted fur where it seems one of her various growths has burst. The liquid isn't pussy or filmy. It's just clear, like water. But it's the third time in as many days that I've found her with a soaked spot, sort of moping around while it leaks. I'm just hoping it's not urine, because that would mean the end is nearer than I want it to be.

Meanwhile, the canine fitness tracker she's wearing—a coin-sized silver disc that attaches to her collar—reports everything is going great. This can't be great, right?

I've been living away from Gypsy (that is to say, out of my parents' home) for 10 years now. But when I moved abroad I decided: I need to be able to know as much about my pup as possible, even in my absence. Second-hand reports weren't enough. So, I decided to strap an activity reader to her and watch the cold, hard data pour in.

I know that everyone says they love their dog, but I really love my dog. My family adopted Gypsy (also known as Roo, Roo Roo, Ooo Roo, Jibba, or Jibba Jabba) when I was in high school—my mom shocked us all when she brought home an intensely affectionate Border Collie-Australian Shepherd mix who was terrified of fireworks and bicycles and loved ice cubes. She is, to be totally honest, the best dog.

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When I went to college, I lived close enough that I could see Gypsy every few months. After graduation, I moved a mere 45 minutes away and saw my dog even more often. But life got busier: My parents didn't bring her on trips to see me (she was getting older, getting into the car became more difficult), and I didn't have as much time to drive home. When I moved to Seattle, about four and a half hours away, I saw her even less. And then, when I moved to the Caribbean, it hit me: Gypsy might die while I'm gone. I might not get a call, telling me to come say goodbye, because it would be impossible.

I was home a few months ago, visiting my family—and my dog. She's always had the manic energy of her breed, coupled with an endearing sweetness; she's seemed like a puppy since the day she came home. But I finally noticed it: She had cysts, her fur was getting matted more easily. Her eyes were a little cloudier and didn't follow you as well. Her back legs struggled to push her up on the hardwood floors; she would slide a bit, sometimes fall down. She definitely couldn't sprint like she used to anymore. She was old.

That's when I decided that if I couldn't be around physically for Gypsy's last months, I would be around digitally. I figured if I couldn't actually be with her, I would use technology to... "be" with her. So I got a Fitbit for my dog.

Not actually a Fitbit, but a Whistle, a $99 canine activity tracker which you often hear described by people who own one as "the Fitbit for dogs." Whistle has a motion sensor and a GPS sensor, so you can see how much exercise and rest your dog is getting. You can include additional info, like how much she's eating. Within the app, you can attach photos you've taken.

Molly McHugh/WIRED

At first, it was fun—adorable, even! I could see how active and playful Gypsy was compared to other dogs similar to her. I could see when she was out on a walk, and how much sleep she was getting. Whistle told me that she had an 82 percent success rate of hitting her goals (75 out of 91 days) and her best streak for doing so was a whopping 20 days. In fact, she's better at meeting her activity goals than most dogs like her, so says Whistle. (She would get an average of 84 minutes of activity a day—similar dogs apparently get around 59.)

I watched from abroad as Gypsy hit her daily quota for activity and zipped past her exercise requirements. I noted to myself that it seemed like she wasn't getting as much sleep as a dog her age and size should (a stat Whistle helps calculate), but hey, too little sleep was surely a sign she was more energetic and less lethargic! A good thing! Each evening, an alert would roll in, "Gypsy hit her goal!" and I felt soothed, comforted: She was old, but was doing fine.

As it turns out, she was only sort of "technically" doing fine. After moving back to the U.S., I made a trip to visit to my parents. While there, I would get Whistle alerts while sitting in the same room as Roo. Her activity report rolls in while I listen to her pant for no reason, or I get her sleep status while her paws struggle against the hardwood floors.

It's not that Whistle is inaccurate—hardly. It's just that when you're not there, actually seeing your dog, the reports don't spell out the entirety of what's happening. Sure, she still meets her activity goals, but Whistle doesn't record how she slipped on a stair. I can see that she's still eating her dinner, which is fantastic, but the device can't show me how confused and panicked she seems when she wakes up—all very obvious differences now that, despite her relative health, are startling. I was somewhat lured into thinking everything was fine, that I would come home to my dog, the ageless wonder. Because on paper (or, screen, rather), that's what I'd convinced myself she was.

Molly McHugh/WIRED

To be honest though, when I jump out and ignore the day-to-day reports and look at Whistle's overall data, I can see the decline—which is such a strange thing to see defined in an app. Usually, these sorts of services are about living better: We want to lose weight or monitor our heart rates, and Fitbits, Fuelbands, and Apple Watches give us shiny charts and graphs so we can analyze ourselves and do so. But what about when a tracker isn't showing that you're getting better—what if it says you're getting worse? If someone were to wear one of these things forever, they'd notice a change from improving their body to watching it die.

Now, I get nervous that I'll see her activity plummet—maybe stop completely. That I'll have a chart that shows me the moment she gave up, or even the moment she died.

Yesterday, we took Gypsy back to the vet to inspect her cysts. The vet told us, though, that it looks like there's a lot of urine in her fur, too—and that she's becoming incontinent. Which means, of course, that her health is worse than we thought. I went and bought pads to put underneath her beds, gave her a thorough bath, and took her for a walk. And despite the vet's warning, she tugged at the leash, wanting to go faster, jumping back and forth (albeit it a little feebly) like a dog half her age.

Molly McHugh/WIRED

I'm about to leave and move away again. I know it's even more possible I won't see Roo after this. So I figured it's time to decide: Do I leave the Whistle on and continue to track her health, even if that means being able to zoom out on the data and literally watch her die? Even though it's scary and sad (because you know, death is scary and sad), I want to. When I can't physically be there to pet her while she falls asleep or take her for a walk, I can log in and see she's resting, or that she just had a particularly active ten minutes.

I know no amount of trackers and technology will keep her alive, but those push notifications remain a comfort. Every time Gypsy meets her activity goal, that alert says that even though she's old and even though she's probably dying, she's still my dog and she's still out there, living as much and as best as she can. The reality isn't as easy to parse as a few colorful pixels—she has good days and bad days, sometimes it's clear she's struggling and other times she acts like she'll live another ten years. The tiny window Whistle gives me isn't the whole story, but it's a little piece of it, and if I'm going to be gone for the end of Gypsy's story, then I'll take whatever part of it I can.