Quantified-Cat: How I Got to Know My Cat By Tracking Her Health & Behavioral Data

With the advances in self-tracking technologies and the prevalence of low-cost tracking devices, “Quantified-Self” (QS), a community where people track their personal data and gain self-knowledge through numbers, has been growing in recent years. Inspired by the QS movement, I did a 2-month “Quantified-Cat” project — tracking and analyzing my cat’s health and behavioral data. This project turned out to save her from a miserable infection and helped me better understand her daily activities.

How Missy looked like in Aug, 2017 and Jan, 2018
What Missy looked like in Aug 2017 and Jan 2018: the same cat, same posture, but different size 😂

In Aug 2017, I adopted a two-year old cat Missy, from a shelter at Washington D.C. Missy was shy and skinny when she first came home, but she was soon able to navigate the new place and of course, to gain more weight.

The Origin of the Story: Chin Acne

Being a chubby cat is adorable, but it sometimes causes problems. In Feb 2018, I noticed that on Missy’s chin, some “black spots” were expanding. After consulting with some friends who also have a cat, I learned that this was a typical skin problem: chin acne, which many cats experience. Although it was not critical, Missy kept scratching her chin so I took her to the vet.

Nervous Missy in the vet (left) and the “black spot” on her chin (right).

The doctor prescribed a skin cream called Mupirocin, and asked me to apply this cream on Missy’s chin while wiping it twice a day. But more importantly, he emphasized that Missy was overweight, which could be the cause of her chin acne and cause more serious health problems (e.g., diabetics) as she grows older. To control Missy’s weight, the doctor asked me to feed Missy no more than 45g dry food per day and to get her do more exercise.

Going back home, I realized that I need a TODO list. Applying the cream should be easy, but how about controlling food intake and taking Missy to exercise?


I started with a set of stick notes and a daily reminder set on my phone. However, it did not work well, as I kept revising my “tracking schema”. I was not able to track all of the information in a consistent manner because Missy’s activities are different every day. Also, it was hard to strictly follow the “45g-per-day” plan, even with a measuring cup. That chubby cat is very good at asking for food, making it difficult for me to say “No.”

The sticky notes I started with tracking Missy’s information.

At that time, my colleague Young-Ho was designing and building a mobile self-tracking app, OmniTrack, which allows people to customize their tracking items and data formats. While helping test the app, I realized that this was what I needed for Missy!

Screenshots of OmniTrack’s interface, which allows users to define multiple trackers, configure the data format, and connect with external devices (e.g., Misfit, Fitbit).

Inspired by a variety of tracking options on OmniTrack, I started thinking about more interesting things I would like to record for Missy. For example, her chin acne condition, weight, how many times I interact with her, and how excited she is (from a human perspective :)). I configured 15 data fields in total, and even tried to get my MisFit Ray on Missy so that I could know her sleep hours and activity level with “actual numbers” automatically!

Missy’s tracker on OmniTrack & her MisFit Ray.

Capturing a New Problem: Yeast Infection

As I followed the prescriptions, the chin acne went away, so I intentionally reduced the frequency of using Mupirocin. However, a new problem occurred: some “yellow flakes” started expanding around Missy’s chin and neck area, causing plenty of loss of her hair.

The estimated amount of “yellow flakes” I brushed from Missy’s chin (left). A timeline of the frequency I wiped Missy’s chin, the frequency I applied Mupirocin, and the estimated amount of “yellow flakes” appearing around Missy’s chin and neck area (right). A few data points were filled retrospectively on the next day.

At first, I thought the “yellow flakes” were something similar to chin acne and did not pay much attention. But soon I realized that it was not a normal skin problem, as those flakes appeared in a different color and shape, which were too stubborn to be brushed away. While keeping monitoring Missy’s other activities and the amount of “yellow flakes”, I visualized her tracking records to examine what might have caused this problem. Reflecting on the data, I noticed that the situation was gradually getting better after I stopped using Mupirocin for a few days, and was then exacerbated when I applied it again. With doubts, I stopped using Mupirocin completely and visited the vet.

After diagnosis, the “yellow flakes” turned out to be a type of yeast infection. Although the doctor was not 100% sure, the use of Mupirocin was likely the cause. To completely remove the infection, Missy received a steroid injection (poor cat :().

Interesting Findings: Sleep and Activity

Tracking Missy’s health and behavioral data not only helped me capture the problematic medicine use, but also led to interesting findings around her daily activities.

Missy’s sleep hours on weekdays (left) and weekends (right).

From the MisFit data, I found Missy sleeps a lot in general, and she sleeps much more (4~5 hours) on weekdays than weekends. Although I had known that cats needed plenty of sleep every day, I did not know it could be that long.

Missy’s activity level on weekdays (left) and weekends (right).

In the meantime, Missy also exercised much more (~4000 steps) on weekdays than weekends. Although MisFit data might not be absolutely accurate, the fact that she has distinct life routines between weekdays and weekends was interesting. Why is that? I do not know. Maybe more sleep led to more exercise, or maybe Missy was pawkier when I was not at home (weekdays), and was lazier when I was at home (weekends). Anyway, considering that Missy consumed more calorie on weekdays, I decided to feed her with more food :)


The “Quantified-Cat” project ended ever since Missy got better from the yeast infection, and it lasted about 2 months. Keeping tracking all of the information every day was hard, but I had a lot of fun in getting to know Missy better. Since then I have tried some other automated pet trackers (e.g., BARTUN Mini), but they were either too heavy for Missy to wear, or has a poor connection with the companion app. The MisFit Ray, although is not designed for cats, turns out to be the best cat tracker so far, with its lightweight and flexible band.

The ways I got Missy to exercise.

Although I stopped tracking Missy’s data intensively with OmniTrack and MisFit, the weight loss plan is still ongoing. I bought an automatic cat food feeder that precisely controls Missy’s food intake, and got many toys for her to play with. I also tried to “walk” her outside once a week (Actually, I think she tried to walk me). Anyway, Missy has lost 3.5 pounds within 3 months!

This article is a summary of a talk I gave at “Quantified-Self” DC Meetup in April 2018. I have received many messages asking how Missy is doing, so I decided to write a Medium post and share the story to more Quantified-Selfers and pet lovers :)

Ph.D. Candidate in HCI @UMD https://www.terpconnect.umd.edu/~yuhanluo/