Dehydration is something that horse owners are most likely to worry about during prolonged hot weather, or when intense exercise makes their horse visibly sweaty. However, it’s worth noting that there are plenty of other times your horse may be at risk of dehydration – and some of them might surprise you. Horse health company Haygain take a look at the causes of dehydration, how it can affect horses and how to ensure your horse is well-hydrated.
What causes dehydration?
Let’s kick off by looking at the different ways horses can become dehydrated. The first and most obvious cause is exercise, as the process of cellular respiration uses water, which, combined with sweating, can lead to dehydration.
The type of feed and forage your horse consumes will also impact how much water he needs. A horse kept at grass 24/7 may get 50L of water from the grass itself, thanks to its incredibly high water content. The same horse kept in a stable and fed haylage all day will only be getting 20L of water from his forage, so you’ll probably observe him drinking more. This can impact horses who are being transported, particularly if they’re only offered dry hay to eat during transport, which has an even lower moisture content. Horses can become distressed and sweat up during transit, too, which will lead to dehydration if they aren’t drinking as much as normal.
Another trigger for dehydration is associated with horses drinking less when the temperature drops. When cold weather arrives, any available water can be very cold, and horses are shown to drink less when the water they’re offered is chilled. The problem is amplified in older horses, who may have sensitive or broken teeth. They should be monitored very carefully and offered tepid water during the colder months.
The risks of dehydration
Horses are actually very resistant to dehydration, their performance only affected with a bodyweight loss of 5% – around 25kg in a 500kg horse. However, there are some significant risks for horses who suffer from dehydration.
When horses do experience dehydration, either because they aren’t drinking enough water or are losing it through excessive sweating, their bodies will draw on water reserves in their hindgut. This is why horses are relatively resistant to dehydration, but this drawing of water can trigger complications. Endurance horses exhibit fewer hindgut noises after races, showing the impact of dehydration on their digestive systems. Less water in the hindgut reduces digestive function and increases the risk of impaction colic.
Dehydration will also cause any mucus present in the airways to thicken, so if a horse is suffering from an inflammatory airway disease (IAD) or an allergic reaction, they may well struggle to breathe even more.
Keep him hydrated
Prevention is always better than cure, so if you know your horse is going to be undertaking strenuous exercise, try adding water to any concentrated feeds he receives. Ensure buckets, troughs and drinkers are full and clean so that even fussy horses are happy to drink from them. The winter can throw up issues for horses who aren’t keen on drinking cold water, so try adding some warm to their drinking water when the temperatures drop.
Feeding steamed forage is another excellent way to increase the water intake of a horse, and it has a range of other benefits for equine health. Steaming hay removes up to 99% of respirable dust – which can contain bacteria, mould and fungi – reduces the incidence of IAD by 65% and improves its palatability. But crucially for those considering hydration, it’s an excellent source of additional water – a bale of hay will have three times as much water content after it’s been steamed.
For more information, visit haygain.co.uk