Shopkeeper Winy Juan Antonio Enriquez runs a small store in Nuevo León, Mexico. Among people in the neighborhood, Enriquez has amassed a steady following of loyal customers.

But there’s one customer in particular who’s the most faithful of them all.

About a year ago, as Enriquez prepared to close up shop in the evening, a lone figure appeared sheepishly at the door. The visitor was a stray dog who looked at Enriquez with pleading eyes.

“He arrived alone, very poorly fed,” Enriquez told The Dodo. “I gave him food, but he was very distrustful.”

After wolfing down that meal, the dog disappeared once again into the night. But that wouldn’t be his only visit.

In the days and weeks that followed, the hungry stray dog would randomly appear at Enriquez’s shop’s front door. Enriquez always welcomed him with a meal — slowly earning the dog’s trust.

“Little by little, he allowed me to touch him,” Enriquez said. “It took me more than a month before he would allow me to pet him.”

He named the dog Carlos.

In time, Carlos began to visit Enriquez’s store more and more frequently to receive a meal. Now, it’s a regular thing.

“He comes every day,” Enriquez said. “In the morning, when I open my business, and at night, too.”

All that food given freely to Carlos comes at a price, but for Enriquez, seeing the dog’s reaction to his kindness more than makes it all worthwhile:

Enriquez isn’t entirely sure where Carlos goes or what he does in between those visits — but he’s happy to do his part in filling his belly and making his tail wag. He’s also hoping to find Carlos a home, though he’s happy to tend to his needs in the meantime.

“[Dogs like Carlos] are living beings who are so often ignored,” Enriquez said. “[But when we show them kindness], they are so grateful.”