Professor Lorenz Eitner, in a letter dated 3 December 1999, has confirmed the attribution to Géricault. He dates the drawing circa 1818-1820, and compares it to a sheet in the Art Institute of Chicago (Album Géricault, fol. 21r) showing a similarly sharply turned neck and explicit detailing of the horse's sex, G. Bazin, Théodore Géricault, Paris, 1992, V, p. 215, no. 1659. A further sheet from the Chicago album (fol. 28r) shows similar hatching and delineation of form to that of the present drawing, Bazin, op. cit., p. 185, no. 1574.
Professor Eitner, in his letter refered to above, considers that "this is a drawing of high quality and exceptionally careful execution".