Ashtyn Gardner, 2, of Mobile, Ala., was taking part in a holiday decoration and crafts event for military families and their children in the State Dining Room when Sunny, a Portuguese water hound who joined the Obama family in August, was brought into the room.
Sunny tried to break free from her handler, and knocked Ashtyn down, The Hill reported.
However, USA Today reported some who witnessed the incident said the little girl lost her balance and fell on her own.
Either way, she got right up and was fine, her father, John Gardner, said.
The Hill said first lady Michelle Obama helped the little girl to her feet and hugged her.
Sunny and the Obamas other dig, Bo, remained in the room without further incident, The Hill said.