A pair of similar spaniels, but enamelled in brown enamel in place of the iron-red in the present lot, is illustrated by W. R. Sargent, The Copeland Collection, Salem, 1991, p. 186, no. 89. See also the grisaille-decorated seated spaniels in the Hodroff Collection, illustrated by D. Howard, The Choice of the Private Trader, London, 1994, p. 275, no. 332, where the author suggests that earlier models of this form had the mouth open and tongue showing, as in the present lot, "but the mouth was later closed so that the additional work in inserting the tongue was not necessary". A related pair of iron-red spaniels with white patches was sold in these Rooms, 11 November 2003, lot 158.