Simone Biles Suffers Gnarly Finger Wound After German Shepherd Attack

Simone Biles' triumphant return home from the Olympics has hit a speed bump ... she says she was just bitten by a German Shepherd, and suffered a gnarly finger wound in the attack.

Biles explained the situation on her social media page Friday ... revealing a massive gash on her right hand.

"Here's an update on my finger that the dog bit me," the 24-year-old gymnast said, adding, "German Shepherds don't play."

Details surrounding the attack are unclear ... but Biles said she was forced to go to the doctor to get a tetanus shot and to make sure everything was OK with the injury.

Biles, though, did not seem shaken up at all over the incident ... even joking, "this dog at the farm just said NOT TODAY."

Of course, Biles had been having a great time in her return to Houston from Tokyo ... she got a hero's welcome at the airport and even got to ride in a parade!