Why the hay in front of your horse deserves a second look

For most horses in the UK, forage makes up the bulk of the diet — somewhere between 1.5 and 2.5 per cent of bodyweight in dry matter each day. That means hay is not simply filler; it is the foundation of digestion, behaviour and respiratory health. So when a horse coughs, struggles with condition, or has had a laminitic episode, the hay net is often the first thing worth examining.

One of the most common questions we hear is whether to soak hay or feed it dry. The honest answer is: it depends entirely on the horse in front of you. Soaking changes hay in ways that can be enormously helpful — and in ways that quietly work against you if you have not thought it through.

What soaking actually does to hay

When you submerge a hay net, water does two distinct jobs, and they happen at different speeds.

• Dust reduction: A short soak of 10 to 30 minutes in cold water knocks down a large proportion of the respirable particles and mould spores that irritate the airways. You can see it in the colour of the water afterwards.
• Sugar reduction: Water-soluble carbohydrates (WSC) — the sugars and fructans that matter most for laminitis-prone horses — leach out more slowly. Meaningful reductions of around 30 per cent typically need 10 to 12 hours of soaking, and warm water speeds the process.

Steaming is the other option worth knowing about. It kills mould and spores effectively without leaching sugars, which makes it excellent for a horse with a dust allergy who does not need a low-sugar diet.

The nutritional trade-offs of a soaked net

Water is not selective. Along with the sugar, it carries away other water-soluble nutrients: potassium, sodium, some phosphorus, water-soluble vitamins and a portion of the protein. Long soaks in warm weather can also encourage bacterial fermentation, which further degrades the feed and can upset the hindgut if the hay is left sitting.

In practice this means:

• Energy value drops. A horse maintaining weight on dry hay may lose condition once you switch to a 12-hour soak. Watch the ribs and topline.
• Electrolytes and minerals need replacing. A broad-spectrum vitamin and mineral balancer plus free-choice salt is sensible for any horse on consistently soaked hay.
• Weight is misleading. Soaked hay is heavy with water. Always weigh it dry, or you may inadvertently underfeed by a kilo or more.

When soaking earns its keep

Soaking is genuinely valuable in two broad situations.

The first is respiratory disease. Horses with equine asthma — historically called COPD or broken wind — react badly to dust and spores. A 20 to 30 minute soak, or steaming, can transform a coughing horse's comfort, especially when combined with good ventilation, low-dust bedding and feeding from the floor rather than a high rack.

The second is metabolic disease. For horses and ponies with equine metabolic syndrome, PPID, or a history of laminitis, reducing WSC intake is central to management. A long cold soak of 10 to 12 hours can bring high-sugar hay into a safer range. It is not a substitute for testing, though — if the hay is very high in sugar, soaking reduces it but does not eliminate the risk, and hay analysis remains the gold standard.

Getting the soak right: a practical routine

The details matter more than most people expect.

• Use plenty of water. A ratio of roughly one part hay to four parts water by volume gives the sugar somewhere to go.
• Keep it cool. In summer, soak for no more than 30 minutes if the aim is dust control, or use very cold water and shade for longer soaks. Never leave hay stewing in warm water for hours.
• Drain properly. Hang the net to drip for 10 to 15 minutes before feeding. A sodden net is heavy and unpalatable.
• Rinse and repeat. Fresh water every time; scrub buckets regularly. The black, sweet-smelling water is a bacterial soup.
• Think about disposal. Do not tip sugar-rich soak water onto a paddock grazed by a laminitic pony.
• Plan for winter. Soaked hay freezes solid in a cold snap. Indoors, a large tub with a lid works well, and steaming becomes far more appealing in sub-zero temperatures.

When dry hay is the better answer

For a healthy, good-doing horse with no respiratory signs and no metabolic concerns, well-made, sweet-smelling dry hay is perfectly appropriate — and it preserves more nutrition, which suits horses in work or those who struggle to hold weight. Soaking that horse's hay simply adds labour, loses nutrients and gains very little.

The takeaway is to match the method to the horse. If you are soaking to manage a specific problem, soak with purpose: the right duration, clean water and a balancer to fill the gaps. If you are soaking out of habit, it may be time to reconsider — your horse's waistline and your routine might both benefit from going dry.