Eric Calleja Jr. reunites with his old dog, Frankie, in Portland on Sunday. Shawn Patrick Ouellette/Staff Photographer

Eric Calleja Jr., of Long Island, N.Y., turns 9 years old on Monday.

He came to Portland to receive his birthday present, a two-day reunion with his dog, Frankie.

Calleja is the son of Eric Calleja, a New York City detective and 9/11 first responder. Calleja died in August from cancer linked to the toxic chemicals he was exposed to while helping search for people in the rubble after the attack.

Last spring, Calleja had to surrender Frankie, a strong bull terrier, when his health was failing. And the muscular and active dog was too strong for Calleja’s wife or son to handle.

“The family had to come in and get the dog out immediately. He was hurting Eric, bumping and knocking him,” said Marilyn Calleja, Eric Calleja Jr.’s mom, in the lobby of the Inn at St. John’s on Sunday.

The surrender happened fast when Eric Jr. was in school, Marilyn Calleja said. When he came home, the dog was gone. It was a shock to him.

“Eric came home and was looking for Frankie. He didn’t get to say goodbye,” she said. “There was no closure for the kids. He was just gone.”

Eric Calleja amid the rubble of 9/11 in 2001. A New York City detective, Calleja died in August from cancer after being exposed to toxins at the site. Submitted by Marilyn Calleja

Eric Jr. missed the dog, as did his older sister, Erica Calleja, 18, who lives in Staten Island.

The boy was sad that Frankie was gone, but after his father died in August, Eric Jr.’s grief over the dog intensified.

He started asking for Frankie. He’d see a white bull terrier that looked like his dog, and ask was that Frankie?

“After his father died he lost everything,” his mother said. “Every day when I drove him to school he’s crying, wanting to see his dog. He didn’t know if his dog was dead or alive.”

She took her son for a Florida vacation to try to get his mind off things. But every time he saw a dog that held some resemblance to Frankie, “He’s like, ‘That’s my dog! That’s my dog!'” she said. “I told him, ‘I don’t know where he is, but I’m going to find him.'”

Eventually, by calling, emailing and sharing pictures of the dog through rescue sites, Marilyn and the woman who adopted Frankie found each other.

Frankie now belongs to Olivia Morrissette of New Hampshire, who enthusiastically agreed to a reunion with the dog for Eric. Jr.’s birthday.

“She’s the sweetest lady,” Marilyn Calleja said of Morrissette.

The Callejas, along with some other family members, flew from New York to Portland to meet the dog Sunday.

Erica, Eric and Marilyn Calleja watch Frankie as he plays with a toy in the lobby of the Inn at St. John during their reunion with the dog Sunday. Shawn Patrick Ouellette/Staff Photographer

When the boy and dog were reunited, “he was going crazy!” and instantly recognized his former family, Eric Jr. said.

“This is the best birthday gift I’ve ever had in my life,” he said, while still acknowledging that he would have to leave Frankie. “But I’m going to see him again next year.”

Eric Jr.’s father, who was 53 when he died, would have been pleased with the reunion, Marilyn Calleja said.

“He was a great father,” she said. “He had two beautiful kids. One thing about him was he loved his kids. He was all about family. He was the greatest husband.”

Eric Calleja Jr. holds his father’s flag after he died last summer. Submitted by Marilyn Calleja

Eric Calleja’s sickness began in 2014 when he and Marilyn were expecting Eric Jr. Initially they were told it “was nothing,” she said.

Eventually he was diagnosed with colon cancer, then bone cancer, then brain cancer. Marilyn made a promise to her husband that if anything ever happened, they would take care of the two children and keep the family together.

“This is what he would have wanted,” she said with tears in her eyes.

Morrissette and Marilyn Calleja said there will be more birthday reunions, probably next time in New Hampshire, where Frankie now enjoys a large, fenced-in yard. At their next visit they plan to stay near her home at a nearby bed and breakfast.

She’s grateful to Morrissette for keeping the dog and inviting Eric Jr. to see him.

Morrissette “is family now,” Marilyn Calleja said.