Striking a horse with a padded racing whip is at least aversive, and at worst, painful [1-3]. As McLean and McGreevy  note, from a behavioural science perspective, for a whip to work, “…it must have acquired the properties of a punisher at some point in time.” An Australian study by McGreevy and colleagues  found 83% of whip strikes caused indentations of the skin, and a recent study in horses confirmed whipping was likely to trigger nerve endings in the skin that transmit pain signals . Despite this, a detailed 2017 study  found that penalties for breaches of whipping rules were too low, and were insufficient to act as deterrents. The authors concluded that “… the whip rules, their surveillance and recording, and the penalties imposed warrant urgent and independent review.”
1. Lewin GR and Moshourab R. (2004). Mechanosensation and pain. J Neurobiol. 61, 30–44.
2. McGreevy PD, Corken RA, Salvin H, et al. (2012). Whip use by jockeys in a sample of Australian thoroughbred races—an observational study. PLoS ONE 7, e33398.
3. Taylor PM, Crosignani N, Lopes C, et al. (2016). Mechanical nociceptive thresholds using four probe configurations in horses. Vet Anaesth Analg, 43, 99–108.
4. McLean AN and McGreevy PD. (2010). Ethical equitation: capping the price horses pay for human glory. J Vet Behav: Clin Applications Res, 5(4), 203-209.
5. Hood J, McDonald C, Wilson B, et al. (2017). Whip rule breaches in a major Australian racing jurisdiction: welfare and regulatory implications. Animals, 7(1), 4.