some reference for artists and others
Svaha (Arabian/mustang mare, bay) demonstrates some basic action.
trot
The trot is a 2-beat gait. Legs move in diagonal pairs: left front/right rear... right front/left rear.
Above: Svaha circling to left, on left lead (left foreleg last to hit the ground, "leading".
canter
The canter is a 3-beat gait.
If the horse is turning to the right, it is on the right lead, the right front leg is the last to hit the ground in the stride. The sequence is left rear... right rear and left fore together... right fore... moment of suspension when no feet are on the ground.
If the horse is turning to the left, it is on the left lead, the left front leg is the last to hit the ground in the stride. The sequence is right rear... left rear and right fore together... left fore... moment of suspension when no feet are on the ground.
If the horse is turning to the right, it is on the right lead, the right front leg is the last to hit the ground in the stride. The sequence is left rear... right rear and left fore together... right fore... moment of suspension when no feet are on the ground.
If the horse is turning to the left, it is on the left lead, the left front leg is the last to hit the ground in the stride. The sequence is right rear... left rear and right fore together... left fore... moment of suspension when no feet are on the ground.
Below: Svaha circling on right lead, turning to right, right foreleg last to hit the ground, "leading".