How hot is too hot to ride?
Experts have shared advice and busted myths on potentially fatal heatstroke
THOSE concerned over riding in heat should consider a number of factors, experts have advised.
As the UK enjoys a scorching summer, worried riders have been asking for guidance.
David Marlin, who conducted ground-breaking research on thermoregulation with the FEI before the 1996 Atlanta Olympics and has since worked extensively on the subject, said a high risk factor for heatstroke is horses unused to high temperatures.
“If they’re normally ridden early or late, then compete in the middle of the day, they won’t be used to it,” Dr Marlin told H&H.
“Even if they are acclimatised, they won’t perform as hard or for as long, as regulating temperature uses energy, and blood that would normally supply oxygen to the muscles is pushed through the skin to help keep the horse cool.”
Dr Marlin said the key issues in heatstroke are the horse’s temperature, and how long it stays at that level. So the animal may withstand five minutes with a rectal temperature of 42°C, but will be unable to cope for 10.
“If you’ve got a hot horse after exercise, get as much water on it as quickly as possible,” he said. “People might get a sponge and dab but if it’s very hot, panting and wobbly on its legs, time is critical. If you cool the horse quickly, you could prevent it collapsing.”
Dr Marlin stressed scraping is not needed; some riders mistakenly believe water warmed by body heat makes horses hotter.
“I don’t know where this has come from,” he said. “The water gets warmer because it’s taking heat from the horse; it’s doing its job and it evaporates, which cools the horse. If you’re hot and have a cold shower, what’s going to cool you more: staying in the shower or repeatedly coming out to dry off?”
BUSTING MYTHS
DR MARLIN said another myth is that turning horses out wet heats them up; in fact the water will evaporate and so cool the horse.
Allowing horses to drink before and “as much as they want, immediately after” exercise is good practice. Applying and offering ice-cold water is fine, although it has been shown horses will drink more if the water is at 20-25°C rather than 10 or 30°C.
“People might think, ‘This doesn’t apply to me because I don’t ride that hard or in the heat’,” Dr Marlin added. “But one day, you might come across a horse collapsed or at the point of collapse, and knowing what to do could save that horse’s life.”
Antony Clements of the British Equine Veterinary Association’s equine sports committee agreed acclimatisation is key.
“Horses can deal well with high temperatures, they’re desert animals,” he said. “What they can’t deal with is sudden changes.
“If a horse is used to exercising in the heat, is fit and has a fine coat, it’s less of an issue.”
Dr Clements saw cases of heatstroke when he worked in South African racing.
“Heatstroke is distressing but cooling them with water is best.
“The most important thing is common sense; and if a horse does have heatstroke, call the vet straight away, and get as much water on it as you can.”
Jo Linton’s mare started showing colic symptoms on 7 July, after a show. As Gwen had been hosed, and drunk water, Jo did not consider heatstroke.
Jo’s vet Eamon Smyth of Equivet gave Gwen electrolytes and medication, and told Jo to keep the hose on her.
Jo said: “It was terrifying and I think a lot of people haven’t experienced this so I want to raise awareness; I was walking her as I thought it was colic but in the heat, that could make it worse.”