Warning: Distressing content
US authorities are investigating after a disturbing video of a woman beating a dog went viral on Twitter, prompting a wave of outrage.
The video, believed to have been filmed in Boise, Idaho, shows a woman wearing boxing gloves punching a german shepherd hard in the face.
As a man films, the woman hits the dog multiple times over the 13-second clip as the man says: "We're boxing animals".
The video shows the dog's head snapping back and forth as the blows land. After the particularly vicious final blow, the dog yelps in pain.
"I hit him so hard," the woman says as the video cuts off.
The Herald has chosen not to publish the video.
The woman was quickly identified online and set her accounts to private after facing a huge backlash.
A social media user claiming to have been in conversation with the woman in the video published a screenshot of a purported conversation where the woman defends her actions.
"That's my dog. He plays hard. A girl gunna hit him a little bit and you guys wanna press some girl hitting him with gloves.
"Never got hurt and was playing the entire time. I'd never let my dog get hurt."
"I do what I do with my dog. He thinks it's a game was he hurt at all in the video or at all?" the texts read.
"He's literally laying with me in bed."
Local authorities later confirmed that they were investigating. The Idaho Humane Society said their Animal Care and Control office received "an overwhelming number" of messages about the video.
"The investigation is currently pending review at the local prosecutor's office for a charging decision," they posted in a Facebook message.
They added that the conduct in the video may fall under Idaho's misdemeanour animal abuse statute, which criminalises "every person who cruelly whips, beats or otherwise maliciously treats any animal".