The Efficacy of Sponge Baths and Hosing on Exercise Recovery in Thoroughbred Horses
Cooling exercised or overheated equines is critical to avoid heat-related illnesses. Applying water is effective for cooling horses1,2, and a hose is commonly used to continuously apply water. However, running water from a hose is not always accessible and a bucket of water and sponge may be a suitable alternative for applying water in these situations.
The objective of this study was to determine if there were differences in heart rates and cooling rates when horses were either sponged, hosed, or walked following exercise.
Eight Thoroughbred geldings (BW: 585±39 kg; age: 11±2 yr) with percutaneous thermal-sensing microchips (PTSM) implanted in their middle gluteal muscle (GLUT) were used in an incomplete 3 x 3 Latin square design over three week-long periods. Weekly, horses completed a 13-min SET on an inclined (3o) high-speed treadmill (max speed: 8 m/s; peak heart rate: 179±15 bpm). Three cooling treatments were applied post-exercise: 1) WALK: walking for 5 min, 2) HOSE: water applied with a hose over the entire body for 5 min, and 3) SPONGE: water applied using a large sponge over the entire body for 5 min (~28 L). Following the cooling treatments, all horses walked for 5 min and then returned to their stalls with overhead fans. Heart rate (HR), using a HorsePal HRM G2 Handle, respiratory rate (RR), and GLUT temperature were taken before exercise (baseline) and then at predetermined intervals for 60 min post-exercise. Changes from pre-exercise temperatures were fitted to an exponential one-phase decay model to determine the cooling half-life (t1/2). Data were analysed using a repeated measures ANOVA.
The treadmill exercise increased GLUT temperatures to 40.1±0.5ºC (pre-exercise: 37.0±0.6ºC). Both HOSE and SPONGE had shorter GLUT temperature half-lives (t1/2) post-exercise than WALK (WALK 33.22±11.10 min; SPONGE 14.88±6.10 min; HOSE 16.00±5.52 min; mean ± SD; P<0.01). A shorter t1/2 is indicative of a faster rate of cooling.
RR returned to baseline by 5 min post-exercise for HOSE, 10 min for SPONGE, and 20 min for WALK (P<0.05). HR of all treatments returned to baseline by 15 min post-exercise and WALK had a higher overall HR compared to both HOSE and SPONGE (P<0.05).
Both hosing and sponging were effective at cooling horses post-exercise and were better than just walking. In this study, liberal amounts of water were sponged over the horse’s entire body. Applying smaller amounts of water to just the neck and head may be less effective.
References:
1Marlin et al. 2010.Equine Veterinary Journal 30:28-34.
2Takahashi et al., 2020. Journal of Equine Veterinary Science 91:103130.