Evolución: Mérida's Largest No-Kill Shelter Running on Empty

On any given morning, Silvia Cortés Castillo walks into Evolución Animal AC and faces a number that would overwhelm most people: more than 600 animals depending on her team for everything — food, medicine, water, and a reason to trust humans again.

Evolución Animal AC is Yucatán’s largest no-kill shelter, a nonprofit that has spent more than two decades absorbing what the street gives up: dogs left chained without food, cats dumped at the side of a highway, animals too sick or beaten down to care for themselves. Right now, the sanctuary outside Mérida holds 460 dogs, 150 cats, 3 pigs, and a rabbit. Every one of them, Cortés Castillo says, arrived as a victim of abandonment or mistreatment.

The shelter stopped actively taking in new animals some time ago — the need has simply outgrown the resources. But that hasn’t stopped people from leaving animals at the gate anyway. Those animals get care. The numbers grow. The budget doesn’t.

“We stopped rescuing and receiving animals because needs are always superior to our resources,” Cortés Castillo said. “Even though people dump animals at our gates all the time.”

Every animal at Evolución is treated, dewormed, vaccinated, and spayed or neutered before being made available for adoption. The problem is that adoption rates are low. Many animals spend not days or weeks at the sanctuary but years — sometimes their entire lives.

The math is hard

Feeding the dogs alone costs MX$122,500 a month (roughly US$6,100) — 196 bags of 25-kilogram kibble at MX$625 each. Cat food runs another MX$48,000 (about US$2,400) for 28 bags of 15-kilogram food. The pigs and rabbit require fresh vegetables, adding another MX$8,000 (US$400) to the monthly bill.

Staff wages — for 4 workers when the sanctuary needs at least 6 — run MX$44,500 a month (about US$2,200). Medicines, veterinary fees, electricity, water, and sanitation costs pile on top. Total monthly operating costs run to around MX$250,000 (roughly US$12,500), and sometimes more.

Volunteers are welcome and genuinely useful. They can come Monday through Saturday from 8 a.m. to 2 p.m. But volunteers, Cortés Castillo notes, can’t come every day. The animals need someone there every day.

The situation Evolución finds itself in is not unique to one shelter. In Yucatán, more than 50,000 dogs and cats roam freely, and an estimated 2,000 die each year in Mérida alone. Research from the Autonomous University of Yucatán found that the stray dog population in Mérida rose sharply between 2022 and 2023, reflecting a crisis that no single organization can solve on its own. Mérida has taken steps toward systemic change — the city recently joined a global initiative for humane management of dog and cat populations — but shelters like Evolución remain on the front line, filling a gap that public programs can’t fully cover.

The sanctuary’s model — heal, sterilize, rehome — is the right one. The adoption pipeline is just too slow. Animals that arrive as emergencies become long-term residents, and the costs compound year after year.

Cortés Castillo has been working on behalf of animals for more than 25 years, and Evolución has been a legally registered organization since 2012. For people who have considered adopting but not yet acted, the shelter’s roster of 460 dogs and 150 cats offers plenty of reasons to reconsider the timeline. Previous coverage here has featured the sanctuary’s animals finding homes both locally and as far away as Canada — proof that the right match is often waiting.

For those who can’t adopt, donations go directly to food, medicine, and the staff who show up every day regardless of what the budget says.

Evolución Animal AC

Location: Carretera a Tanil, Fraccionamiento San Lorenzo, Umán (south of Mérida)
Animals in care: 460 dogs, 150 cats, 3 pigs, 1 rabbit
Monthly food cost: approx. MX$178,500 (US$8,900)
Total monthly operating need: approx. MX$250,000 (US$12,500)
Volunteer hours: Monday–Saturday, 8 a.m.–2 p.m.
Founded: 1990s; registered AC since 2012
Website: evolucionanimal.org
Adoptions, donations, and volunteer sign-ups are available through the website