Since 2009, all jockeys in Thoroughbred racing in Australia have been required to use a whip which is padded at the end, replacing conventional whips which have no padding, This change was introduced in response to concerns raised about the pain caused by the use of whips and the introduction of the padded whip in other countries.
The results from one study suggest that, when used in accordance with current racing whip rules, padded whips have less potential to cause pain and damage than conventional whips (which have a double flap of leather at the end). However, there is no evidence to indicate that padded whips cause no pain or damage. Both types of whips cause indentation in the area of impact: the degree of indentation varies with the force of the strike.
Where the unpadded shaft of a padded whip comes into contact with the horse, this section of the whip will cause a similar level of pain as occurs with a conventional whip. One Australian study which analysed video footage of horse races, showed that the whip struck the horse in the abdomen more than 75% of the time and that a visual indentation from the whip was seen in over 80% of strikes .
Repeated striking with a whip (of any type) in the same area of the body has the potential to cause localised trauma and tissue damage, the extent of which will increase with the force of the strike and the number of repetitions.
There are therefore three main ways to reduce the pain inflicted by whips: to use a design that has shock-absorbing characteristics; to limit the force applied in striking the horse (through limiting the height and angle of the jockey’s arm); and to limit the number of times a horse can be struck.
Finally, if the intention of using the whip is to signal to the horse to accelerate, then the horse must be given time to respond before the signal is re-applied. Repeated application of the whip when a horse has accelerated will merely confuse the horse or will be interpreted as a signal to decelerate.
The RSPCA advocates for an end of the use of whips as a performance aid in Thoroughbred horse racing.
 McGreevy, P, Corken, R, Salvin, H and Black CM (2012) Whip use by jockeys in a sample of Australian Thoroughbred Races – an observational study. PLOSONE DOI: 10.1371/journal.pone.0033398