Tsuda told the news station she left her daughter unattended just long enough to go to the restroom. When she returned, she found Mana biting the infant.
"I have no words to explain my pain," Tsuda told KHON in a statement.
Las Vegas police said the mauling appeared to be a tragic accident and that charges were not likely to be filed against the parents, Las Vegas Now reported.
A GoFundMe page was set up Tuesday to help the family with medical bills and funeral expenses. The page described Kamiko as "a happy and loving daughter, granddaughter, great-granddaughter, niece and cousin."
"We just want to thank you in advance for any help and support," the family wrote. "Aloha (goodbye) and mahalo (thank you)."
KSNV News 3 in Las Vegas reported that Mana was put down Tuesday by Clark County officials. A county spokesman said that a dog that killed a person could not be put up for adoption.
Mark Gibson, a dog trainer and behaviorist, told the news station that dogs, which are pack animals, feel the urge to determine hierarchy when a dominant person or dog is not present. Family dogs are also sometimes jealous when a small child is introduced into the mix.
More often, dogs just want to play, Gibson said.
"So the dog may have had no malice whatsoever toward the baby," Gibson told the station. "But it just got so rough with it, that it was having a fun time chomping and biting and the baby was killed because of it."