A mummified dog first suspected to be a recent burial turned out to be at least 1,200 years old, and its missing teeth revealed the genetics behind one of the Americas' oldest recognized dog types.

Hairless puppies at a 1,200-year-old ceremonial site in Peru ate diets that looked much like those of human children, according to a study in the Journal of Anthropological Archaeology. The pattern hints that people in the Wari Empire may have been deliberately raising these dogs centuries before the Inca rose to power.

The research team, led by Dartmouth College's Weronika Tomczyk, analyzed dog remains from Castillo de Huarmey, a Wari site about 190 miles north of Lima occupied from about 600 to 1050 CE. Dartmouth first announced the findings in May, and the college recirculated them this month through ScienceDaily.

Beyond archaeology, the work shows how the chemistry of bones can reveal how people shaped the diets and lives of the animals around them, a question that still matters for how communities manage dogs and other animals today.

A Mummy That Looked Too Recent

Castillo de Huarmey covers about 110 acres and is the only Wari site discovered so far on Peru's northern coast. Excavations there in 2012 uncovered an undisturbed elite tomb holding 58 high-status women, six human sacrifices and about 1,300 artifacts, and in 2022 the team found burials of elite craftspeople with gold, silver and bronze tools.

The investigation began with a puzzle. Looters had disturbed large parts of the site after a 1970 earthquake, mixing its upper layers, and one well-preserved mummified dog seemed out of place. The researchers at first suspected it might have been buried relatively recently, perhaps about 50 years earlier during the looting.

Radiocarbon dating settled it. The mummified male dog is at least 1,200 years old, the oldest radiocarbon-dated specimen from the site so far.

The teeth told the rest — in three notable dogs, including a mummified skull with hairless skin, attached ears, and red cinnabar paint, the first premolars had never erupted, and some last molars were also absent. Tomczyk explained that the same gene responsible for hairlessness in dogs also reduces the number of teeth, making the missing premolars a skeletal fingerprint of hairless dogs.

That makes these remains some of the first physical evidence of hairless dogs at a Wari site. A variation of the modern breed is recognized by the American Kennel Club as the Peruvian Inca Orchid. Peru recognizes today's Peruvian Hairless Dog as part of its cultural heritage, a designation made in 2000.

Bone Chemistry Points to Careful Feeding

The team analyzed carbon, nitrogen, oxygen and strontium isotopes in the remains. These chemical signatures record what an animal ate and where it lived. Most dogs at the site ate at least some maize, as did the people.

The hairless puppies stood out — their diets resembled those of human children, then became more varied as they grew. Tomczyk said in a Dartmouth release that the distinct pattern provides insight into "what may have been organized breeding."

Burials point the same way. A puppy about six to eight weeks old was buried with an elite craftsperson known as the Master Basketmaker. An adult dog was buried within the palace, and part of a puppy skeleton accompanied a man who was probably sacrificed as a tomb guardian. A ceramic vessel from the site shows a seated hairless dog with humanlike features.

Few bones show butchery marks, suggesting dogs at Castillo de Huarmey were rarely eaten.

Pets, Pests and the Limits of the Evidence

The study does not prove the dogs were bred under a formal program. The researchers say they cannot tell whether the dogs were intentionally fed maize or ate scraps and trash. The isotope pattern is consistent with controlled feeding, but it is not direct proof.

Co-authors from the University of Warsaw and the University of Pittsburgh worked with Tomczyk on the analysis, drawing on excavations that ran from 2010 to 2025.

The sample is also modest. The team examined 341 bone specimens from at least 19 dogs, plus the mummified male, at a single site, so the findings may not reflect dog keeping across the whole Wari world.

Treatment varied as well. Some dogs were carefully buried, while others turned up among discarded material. Tomczyk noted that "a pet for one group of people could at the same time be considered a pest" by close neighbors, according to ScienceDaily.

That tension is familiar today. In many U.S. communities, the same animals are cherished pets in one household and nuisance or stray animals to the next, a reminder that the relationship between people and dogs has always depended on who is doing the caring.

Lessons From a 1,200-Year-Old Kennel

For readers, the takeaway is how much a few teeth and a chemical signature can reveal. Isotope analysis, the same family of tools ecologists use to trace diets and migrations in modern wildlife, is turning up evidence of human choices in animal lives long before written records.

Future work could test whether other Wari sites show the same feeding pattern, and whether ancient DNA can confirm the hairless-dog lineage directly. Those results would show whether Castillo de Huarmey was unusual or part of a wider tradition.

The bottom line: hairless puppies at a pre-Inca ceremonial site appear to have been fed like children and buried with elite residents. The evidence points toward organized breeding, but the researchers stop short of calling it proven.

What Readers Want to Know

What did the study find?

Isotope analysis showed hairless puppies at Castillo de Huarmey ate diets resembling those of human children, hinting at organized breeding.

Where is Castillo de Huarmey?

It is a Wari Empire site about 190 miles north of Lima, Peru, occupied from about 600 to 1050 CE.

How did researchers know the dogs were hairless?

The first premolars never erupted. The gene linked to hairlessness also reduces tooth numbers.

Why did researchers think the mummified dog was recent?

Looters had disturbed the site, so the team suspected a burial from about 50 years ago. Radiocarbon dating showed it is at least 1,200 years old.

Were the dogs eaten?

Few bones show butchery marks, suggesting dogs were rarely eaten at the site.

Is the study new?

It was published in the Journal of Anthropological Archaeology earlier in 2026. Dartmouth announced it in May and recirculated it in October.