What breed of horse is aspercel from the horse in the grey flannel suit?

Aspercel, the horse in "The Horse in the Gray Flannel Suit," is portrayed as a Thoroughbred. This breed is known for its speed, agility, and endurance, making it a popular choice in racing and other equestrian sports. The story highlights Aspercel's unique qualities and the bond between the horse and its owner, emphasizing the deep connection that can exist between humans and animals.