Horses evolved as free-range herd animals, eating at will, so can suffer ill-effects from being confined to a small space for long periods.
Considerable research has been devoted to finding ways to mitigate the social, nutritional and health issues caused by stabling. While it is inevitable that many horses spend more time indoors over winter, we can greatly improve their lives with a little thought and a willingness to challenge the preconceived ideas of how they should be kept.
Many notions about stabling date from the Victorian age. One such concept is stable design that precludes continuous visual and tactile contact — where the only opportunity for a horse to see his companions is when he and another are looking over the stable door at the same time.
It is not surprising that animals naturally suited to living in groups will often show a failure to adapt to solitary confinement. Where horses are kept alone, studies have found a reduction in time spent lying down, plus stress behaviours appear more frequently and horses develop stable “vices” (stereotypies), such as weaving or box-walking.
Fitting bars or grills between stables or making a “talk hole” in the partition wall will enable essential social contact, provided that neighbouring horses get on. A stable mirror made of safety glass can also provide companionship, although social interaction with real horses is preferable.
A stabled horse needs space to move, stretch and roll. An area of 12x12ft is considered a minimum, although horses measuring larger than 16hh will require more room.
The quality of the air within this space will reflect a balance between the rate of release of dust particles, fungal spores and ammonia (produced by urine) from the bedding, and the rate at which these are cleared from the stable air.
Several studies have shown that most horses bedded on straw — not just those with equine asthma — have a significant number of fungal spores and evidence of inflammation in the lower airways. These horses may show no external signs of respiratory disease; their performance may be subtly impaired, however, especially in disciplines with high oxygen demands, such as racing or jumping at speed.
While the adverse effects of straw bedding can be partially mitigated by good ventilation, the optimum of four complete air changes per hour can never be achieved in a conventional 12x12ft stable with an open half-door and a small window.
It is not usually possible to objectively judge how “dusty” the air in a stable is, but this can be inferred from the type of bedding used. A persistent smell of ammonia from urine will suggest that ventilation is poor.
Feeding haylage, or soaked hay, and using dust-free bedding will greatly improve air quality. Dust-extracted shavings or miscanthus, otherwise known as elephant grass, are good bedding options for horses, although studies have shown chopped cardboard to be the best.
There are various ways to further improve the air your horse breathes:
- Dust particles peak as you muck out and for several hours afterwards, so try to turn him out before you start.
- A second peak occurs when the bed is “pulled down” for the night. There is a case for eliminating this practice completely, by scattering powdered lime on the urine “footprint” while mucking out and preparing the evening bed straight away — thus turning over the bed only once.
- Promote good airflow in the stable by removing the glass from windows, using a bar or chain across the doorway when practical and not closing barn doors at night unless strictly necessary. Provide additional air inlets and outlets, as far away from the stable door as possible.
- Bedding banks, sometimes used to prevent horses from becoming cast, are typically left undisturbed and are common sites for fungal multiplication — even when dust-free bedding is used. If you create banks, pull the bedding in from the edges frequently to ensure all areas are fresh.
Stabling is a key risk factor for colic and exertional rhabdomyolysis, sometimes known as azoturia or tying up. Studies have shown that if time indoors is increased from zero to six hours to 19 to 24 hours, impaction colic risk increases by a factor of seven.
Confinement decreases the frequency of large intestinal contractions, reducing both fibre digestibility and the water content of droppings. Exercise, or at the very least some turnout, every day, is hugely beneficial — both mentally, allowing social interaction with other horses, and physically, ensuring the normal function of the digestive and musculoskeletal systems and providing access to clean air.
While exercise is generally desirable, there is evidence that horses given a minimum of two rest days per week have a much lower incidence of gastric ulcers.
Conventional twice-daily rations of hard feed, especially those containing cereal grains, further increase the chance of colic and also cause large shifts of acidity of the stomach — a known predisposing factor for gastric ulceration. Small, frequent meals are preferable, ideally using feeds high in oil and low in starch. Adding alfalfa chaff (preferably dry) increases salivation, helping to neutralise stomach acid.
Reduce reliance on hard feed by providing the highest quality forage you can find. Hay or haylage should be soft, green and leafy and fed ad lib, so there is always some left in the morning.
Provide forage in more than one place in the stable, to satisfy the horse’s strong natural motivation to eat and move, and use a hay bag, or a small-hole or double haynet to slow his intake. Placing some forage at floor level will vary his neck position and elevate his spine when eating, promoting natural drainage of respiratory secretions and ensuring correct alignment of the cheek teeth when chewing.
Studies on human athletes have shown that a good night’s sleep is critical for optimum performance. Deep sleep, also known as rapid eye movement (REM) sleep, can only be achieved if the horse lies down on his side or sits propped against a wall.
Research has shown that the duration of recumbent sleep in the horse is affected by the type of bedding, its depth and the size of the bedded area. Straw is said to be best, although this can create the respiratory issues already discussed.
The current minimalist approach of a thin bed laid on rubber matting, covering a smaller floor area, may have implications for how much REM sleep a horse obtains. This may be a case where the traditional practice of providing a more substantial bed is best.
Ref Horse & Hound; 12 September 2019