My 11 year old WB has developed strange skip in his trot for the last couple of months. Ultrasound of his legs is good, hock x-rays are clear and front fetlocks/hooves x-rays are clear. He is willing to work, full of energy, trots forward. But sometimes he would add an odd hop or skip in trot, like he would jump to canter (but doesn’t). It happens many times during the ride(5-15), and happens when he is going in straight lines. He does it out of blue. He lifts his neck and head and skips and then just goes on like nothing happened. Sometimes he can trot for 5 minutes (circles, changes, straight) and go forward and on the bit, and then suddenly he just skips. He is currently in medium/light work due to this issue. He lifts his head up when the right front hits the ground and before he lands on the right hind his head and neck are in the air, like he takes all the weight to left hind before landing on right hind. Or it could be the right front. He really engages himself over the poles for example, no skip/hop, and then when going around the arena he just skips. My vet said he is a huge horse (around 175cm tall) that needs to be in constant work, and says it might resolve when the horse gets fit. So no lameness, just a strange skip here and there, any clues? Any experiences and/or help appreciated!