Ana Prado, 26, of Henderson, Nev., told arresting officers she was in Boston to answer a court charge of drug trafficking. Witnesses said they saw her striking and kicking a small dog and suspending the animal in the air by its leash in the ladies' room of the South commuter station Thursday, The Boston Globe reported Friday.
The dog is believed to be a Yorkshire terrier, transit police said.
Prado was booked at Transit Police headquarters on cruelty charges, and was arraigned in Suffolk County, Mass., Superior Court, where she pleaded not guilty, court documents said.
Animal control officers seized the dog and took it to veterinarian for evaluation, the newspaper said.