Hydration for horses: How to keep your horse hydrated in winter

It’s easy to think that dehydration only affects horses in the warmer summer months when they are hot and sweating a lot. However, frozen drinking water and dropping temperatures in the winter months can result in some horses actually drinking less, increasing the possibility of dehydration.

Keeping horses hydrated in winter can be a challenge, largely due to the climate and food sources available. Water intake is intrinsically linked with appetite, and a horse which has a reduced appetite for any reason, or reduced food intake due to scarce food supply, will inherently drink less water. 

Horses tend to receive more hay or haylage than grass in winter compared to the summer months, which is a much drier diet. Grass is around 80% water in composition, and this water must be replaced by an increase in drinking by the horse if they are to remain normally hydrated on winter rations. Horses should have forage (hay/haylage or grass) available constantly, unless there is a medical need for restricted rations. 

Hydration for horses

There are potentially serious consequences to a horse not drinking enough water.

First, dehydration can affect the horse’s digestive system and increase the risk of colic. Horses store large amounts of water in their gastrointestinal tract and if the contents become too dry, this can lead to impaction colic. This tends to be exacerbated in winter, when horses are stabled more, exercised less and eat an increased amount of fibre, such as hay.

Second, a dehydrated horse can be more prone to respiratory infections or the worsening of conditions such as recurrent airway obstruction. This is because the mucous lining the airways thickens and clears more slowly from the lungs.

Signs of dehydration

Signs that a horse may be dehydrated include:

• Increased dryness/firmness of the faecal balls, possibly associated with smaller piles of faeces or less frequent defecation.
• Urine becoming more concentrated – there will be fewer wet areas in the bedding and, if urination is observed, the urine may appear darker and thicker than normal, with reduced volumes.
• Gums appearing dry, tacky and less moist than usual.
• Dark red gums and inside of eyelids, rather than a healthy salmon pink.
• Decreased performance levels.

Left unaddressed, your horse may become lethargic and is at risk of developing an impaction of faecal material in the bowel. This is where dry matter accumulates in the large colon and leads to colic, as the bowel expands and becomes painful. Colic requires urgent veterinary attention, and could lead to a hospital visit and a claim on your horse insurance policy.

If you are concerned about reduced faecal output or if any signs of colic are observed, contact your vet promptly to have your horse checked over.

Five ways to hydrate a horse

To help ensure your horse’s hydration, follow these steps.

1. Soak your horse’s hay rations and add plenty of water to bucket feeds to make them wet/sloppy. 
2. Break or melt ice on outdoor troughs every day and take time to check that automatic drinking systems are not frozen. In sub-zero conditions, floating an apple in your horse’s water buckets can help to slow down the freezing process, due to the bobbing motion of the apple.
3. Horses will be less likely to drink very cold water, so once any ice has been removed from buckets and troughs, it helps to add some hot water to the water source as often as you can – warmer water will encourage horses to drink. 
4. Provide water buckets with chopped apples in or add water from the remains of the soaked sugar beet. 
5. Adding salt to daily feeds can also help to increase a horse’s thirst.