An abandoned puppy in Mexico got a happy ending, after being left on a park bench by his owner. Marcela Goldberg, who runs local animal shelter Mascotas Coyoaca, heard about a seven-month-old golden retriever mix chained to a bench in a nearby park. When she went to find the pooch on November 22, she discovered him along with a heartbreaking handwritten note.

“It hurts a lot to leave my dog here but I made the decision of leaving him because my family used to mistreat him and it would always hurt me to see him in that condition,” the note read. ”If you’re reading this and your heart wavers, please adopt him and take good care of him. If not, please leave this note in its place. That way others can read it and adopt him. Thank you.”

Fortunately, the dog was in good physical condition, but had been left without food or water. Park-goers tried to help the dog, but he would attempt to bite anyone that approached out of fear, Marcela told PEOPLE. They had to use a long stick just to get him food and water.

“When I tried to approach him, he was growling and tried to bite me, but it was clear that he was just nervous and not plain aggressive,” Marcela said. Luckily, with the help of a trainer she was able to safely unchain the dog. Being freed completely changed the dog’s attitude.

“He was extremely scared but did not try to bite again,” she added. “We walked him to the car and had to struggle a bit to get him inside, but once inside he started to relax and we were able to touch him.”

Marcela shared the story on social media, writing that she’s given the dog a new name for his new life. “He will no longer be called Max, as his name appears in the note, because he awaits a new life without remnants of his past life, of abuse and neglect. Now it will be Boston,” she wrote.

“He’s a sweetheart,” she called Boston in another post. When news of the story broke, the shelter was met with a lot of interest in adopting the dog. “We can only pick one, but we have many puppies looking for homes,” they wrote on their Facebook page. “If you can open your home to another, we’ll thank you immensely. Their stories are just as sad, but got less media.”