Metro Meteor, a 10-year-old thoroughbred from rural Maryland, was forced to finish his racing career early because of his bad knees.
He was adopted by Ron and Wendy Krajewski in 2009 before learning how to paint using his mouth.
The artistic animal has become an overnight celebrity, with his critically acclaimed work selling for thousands of pounds.
‘Art scholars are not going to have long lengthy discussions trying to decipher the hidden meaning to Metro’s paintings. He is a horse,’ explains his official website.
‘It is what it is. A painting you can hang on your wall and tell all your friends it was painted by a horse.’
Clamping down on the paintbrush using his teeth, Metro spends one or two hours, up to four times a week, creating his masterpieces.
The Krajewskis sell his colourful work, which features specks of sawdust and sweeping brush strokes, online and at an art shop in Gettysburg, Pennsylvania.
‘For his large paintings, there is a waiting list of 120,’ Mr Krajewski said this week.
They use the money to pay for his medical bills and donate the rest to the New Vocations racehorse adoption charity.