Two-year-old Luca Romero of Colleyville has been around animals his whole life, his mom Allis Cho said.

"He's pretty gentle because we have a German Shepherd at home, so we teach him not to hit the animals, to be gentle with them," she said.

But what happened to Luca last weekend, his mother fears, will have life-long effects on the toddler.

"It was very very traumatic obviously," she said.

Luca's family was at Klyde Warren Park in Dallas Saturday at the same time a pet adoption event with Dallas Pets Alive! Cho said they got permission to pet a dog identified by the group as Rusty. They did, then continued walking around, and eventually she and her son returned to Rusty's area.

"He probably only took two or three steps, and then the dog lunged out and bit him in the right arm and chest," Cho said.

Photos of Luca's injuries show how serious the incident was. His mother said fatty tissue was coming out of two puncture wounds.

"It wasn't just a bite where you just bite and release—it bit him and drug him to the ground would not let him go," Cho said. "Four or five men had to come in and pry the dog off of him."

The dog is now under quarantine and being evaluated at Dallas Animal Services. The family is calling for Rusty to be euthanized.

"If it hurt somebody else or killed a child, I don't want that on my conscience," Cho said.

Dallas Pets Alive! says the safety of potential adopters and children is always their first priority.

"We are currently in the process of reviewing what happened," they wrote in a statement, "and cannot share additional details until our investigation is complete. This was an isolated incident, and we are reviewing all of the factors at play to prevent this from happening again."

The toddler has five stitches and a new fear of dogs, Cho said. And though the family doesn't ever want to see dogs be euthanized, they feel in this case, there's no other option.

"We just don't want anyone else to get hurt in the future," Cho said.