Background

A pet’s name can reflect the owner’s humour, social background, and how “human” they think their pet is. A pet usually has a formal name and a nickname.Yet we rarely see systematic data on how people actually use formal names and everyday nicknames for their pets.

The data used in this project offers a chance to look behind jokes and anecdotes. Hundreds of owners reported both the full name and the everyday nickname of one pet, along with the pet’s species, breed and age. This makes it possible to ask questions such as:

The rest of the story uses a series of visualisations to explore these questions and to show what pet names can tell us about our relationships with pets.

Data and cleaning

The dataset comes from github: petnames/PetNames.tsv at master · jgolbeck/petnames · GitHub. Each row represents one pet. The variables include:

For this project I focused on pets that have both a formal name and an everyday nickname. In addition, the dataset needs to be cleaned thoroughly since there are cases where the formatting is misaligned. Therefore, I cleaned the data by trimming extra characters and converting names to lower case, grouping pet types into Dogs, Cats, and Other, removing exact duplicate records.

What do our pets’ names reveal about how we see them?

Are formal names really longer?

The first chart compares the average number of characters in formal names vs everyday names for dogs, cats and “other” pets. Across all three pet types, the formal names are clearly longer than everyday names. For example, cats’ formal names are on average about three characters longer than their nicknames. This indicates that owners like to give their pets long full names, but fall back on something shorter and easier in daily life. In this situation, there is no difference between people’s attitude of pet names and their attitude of humans. They tend to call their pets by nicknames in daily life.

What’s the differences among breeds?

Let’s look at breeds. For each pet type, I selected the five most common breeds and calculated the mean difference in characters between the formal name and the nickname.

The chart shows that Among cats, “Domestic Shorthair” and “Unknown / Mixed” have the largest positive differences — their formal names are noticeably longer than the nicknames. For dogs, breeds such as Golden Retriever stand out: their owners seem especially keen on grand full names. In the “Other” category, Betta dominates and has extremely large differences. This suggests that owners of small pets like fish often use playful formal names but still rely on short everyday nicknames. Therefore, not only which species the pet is, but also what kind of cat, dog, or other animal influences how we name them.

How are nicknames formed from formal names?

To understand how people construct nicknames, I classified each pair of formal name and nickname into five patterns:

  • Shortened/modified from formal name: small edits or truncations (“charlotte” → “charlie”).
  • First word of full name(e.g marie curie → marie)
  • Inside full name(e.g miss kasey bubbles → kasey)
  • Exact the same
  • Totally different

In this part, we use the edit distance (e.g. Lucy to Lulu) to define “Shortened/modified from formal name”(Levenshtein, 1966).

The Sankey diagram links these patterns to pet types. Overall, the largest flow comes from “Totally different”, followed by “Exact same”. This means many owners either reuse the same name in all situations, or give their pet a completely unrelated pet-name.

Which nicknames belong to cats and which to dogs?

For the 15 most common nicknames, we draw a mirrored bar chart:

From the chart, we can see names like “charlie”, “daisy”, “max” and “sadie” lean strongly to the dog side. “Kitty” is unsurprisingly purely a cat nickname. Names such as “lucy” and “lily” are used for both species.

This chart reveals that some nicknames are strongly associated with one species(sounds like dog/cat names), while others are general.

Do some nicknames belong to younger or older pets?

Finally, we explored the age distributions for the ten most common nicknames. The horizontal boxplots show, for each nickname, the distribution of pet ages.

“Max” and “Buddy” have boxes close to older ages, indicating that pets with these names tend to be slightly older in this sample. “Lucy” and “Jack” have more observations on the younger side. Some names, like “Kitty” and “Maggie”, cover a wide age range.

Some nicknames are more common among older pets, while others are more popular among newer pets. This indicates that pet names follow certain trends over time.

Conclusion

From all the charts above, we can see that pet owners generally give their pets a formal name and an everyday nickname, and the formal names are clearly longer, especially for “other” pets such as fish. Different breeds also have their own naming styles: owners of some breeds are particularly fond of long formal names. Many nicknames are actually newly created or exact the same as their formal name rather than simple abbreviations of the formal names. Some nicknames are strongly tied to either cats or dogs, while others are shared across both species. The age distribution shows that nicknames also have a “sense of era”: some are more associated with “older-generation” pets, whereas others belong to a “new-generation” of pets.

These visualisations showcase an interesting conclusion: pet names are not chosen at random, but instead related to breeds, stereotypes, owners’ creativity and naming fashions that change over time.

References

Levenshtein, V.I. (1966) “Binary codes capable of correcting deletions, insertions, and reversals,” Soviet Physics Doklady, 10(8), pp. 707–710. viewed November 20, 2025, <http://profs.sci.univr.it/~liptak/ALBioinfo/2012_2013/2011_2012/files/levenshtein66.pdf>.