Badal the horse keeps on changing throughout the movie from being completely white to having light gray patches on its body.
When Moti the dog is shown driving the horse cart, it is clearly visible that a dummy of the dog was used instead of the real dog.
When a horse and cart fall from the bridge and into the quicksand, the horse is clearly a prop horse.
When Badal the horse brings the baby Raju to Satyen Kappu and his wife, they miraculously know the name of the horse.