It may never be clear what triggered a family pit bull into attacking 1-year-old girl in their Falmouth home on Sunday, but it is clear that the individual animal is to blame, not the pit bull breed, according to the Massachusetts Society for Prevention of Cruelty to Animals.

“What happened is tragic and awful,’’ said Michael Keiley, director of the MSPCA’s adoption program. “But for those of us who have worked in animal welfare for a long time . . . there are many situations where a family pet may act aggressively, and it has nothing to do with the breed. It has a lot to do with the individual child, the individual animal.’’

He said unless an adult witnessed the moments leading up to the attack, it may never be fully understood what triggered the attack on the young girl. “It could be anything,’’ he said, including startling the dog, or not interfering with the animal as it tried to eat or chew on a bone.

The child was airlifted to Boston Children’s Hospital for treatment of injuries to her face that police described as “major trauma.’’

Relatives of the toddler have launched a GoFundMe campaign for the family that has raised $22,780 in 19 hours, double the original goal of $10,000, according to the site. The girl is identified as Remmy and her parents as Stephenie and Reece.

“As many of you know, Remmy is at Boston Children’s (Hospital) for an undetermined amount of time. While there, she will undergo multiple surgeries,’’ the posting reads. “Your donation will help with incoming medical expenses, as well as accommodations so Reece and Stephenie can stay close by at all times.’’

According to Falmouth police, the pit bull-terrier had been part of the Goulart family living in a Brick Kiln Road home for about five years when it attacked the child in the kitchen around 9 a.m., Sunday, while the father was nearby.

Reece Goulart first tried to separate the child and the animal, and when that was unsuccessful, he tried to shoot the dog but realized the gun was unloaded, police wrote. He then grabbed a knife and stabbed the animal until it died.

Susan L. Moran, chairwoman of the town’s Board of Selectmen, said she considered the child’s father a hero for acting to protect his daughter at risk of being attacked by the dog himself. Moran said she does not know the family and her knowledge of the case is limited to details released by police.

“I think that he’s a heroic father who was so completely reactive to make every effort to save that baby and to himself at great risk,’’ she said Monday in a telephone interview. “Our thoughts and prayers are with the family, just really hoping for the best. This is the most tragic thing I could imagine.’’

Moran said there are concerns about dog attacks on Cape Cod and in her town, but she said she did not see the value of immediately banning anyone in town from owning a pit bull.

“I think that would be an overgeneralization,’’ she said, adding she is open to discussing how to respond to the dog attack. “I certainly think this incident should be reviewed . . . [But] smaller dogs can cause injury as well and also no matter how vigilant you are. It seems to me this was really a tragic accident that the father responded to heroically.’’

Keiley said the MSPCA does not issue a special warning to families, especially those with children, when they seek to adopt a pit bull. Last year, the MSPCA adopted out 192 pit bulls, he said.

The breed, he said, receives negative press attention in the same way rottweilers and German shepherds were perceived to be dangerous breeds following high-profile attacks on humans years ago, but no longer are considered a threat to humans.

“We feel strongly that pit bulls are individuals,’’ he said. “I have personally done many, many adoptions with pit bulls into homes with children and feel . . . that this is a very secure situation for the dog, the [family], and the child. There are many wonderful pit bulls in homes with kids.’’

Last year in Lowell, a pit bull attacked and killed a 7-year-old boy who came near the fenced backyard where the animal was kept. And nonfatal pit bull attacks were reported in Amesbury, Brockton, West Bridgewater, Norton, and Cambridge, The Boston Globe has reported.

John R. Ellement can be reached at ellement@globe.com. Follow him on Twitter @JREbosglobe.