As the filly surged forward to hold off the challenger from behind, the jockey noticed she started making a funny noise, like she was choking, then she just "ran out of steam." She dropped from first place to fourth place in two strides.

The above description is typical of a horse which has displaced her soft palate during a race. Right when the horse needs a last burst of energy, it appears as if someone turned off a switch. Horses with dorsal displacement of the soft palate (DDSP) characteristically make a "choking" noise as they slow down from the resulting partial airway obstruction, hence the term "choking down" to describe them