Arguably and at least at first look, the perfect environment for your horse is to live outside in the fresh air, grazing for 16-18 hours a day on fresh forage (grass) as they evolved to do. This is what best meets their physiological needs for digestive, respiratory and muscular skeletal health. However, for many practical reasons such as not enough grass, too much grass, poaching of the ground, clay mud in winter, weather, risk of injury etc a lot of horses spend at least some of their time in the stable.
There are many unseen threats and challenges to stabled horses which need to be addressed to keep the atmosphere as close to their their natural environment (outside, eating grass) for them to stay healthy and perform at their best.
It is well documented that the stable environment exposes horses (and humans!) to high concentrations of dust which includes mould spores, pollen, fungi, dust mites, bacteria as well as physical dust e.g. plant, sand and soil particles. This exposure, especially to the respirable fraction can lead to airway inflammation and respiratory disease such as Equine Asthma in varying degrees of severity.
Air Quality For The Lungs
The main factors relating to air quality in the stable are the hygienic quality of the conserved forage – hay and bedding, the flooring and the ventilation. A recent large-scale study of over 700 sport horses revealed straw bedding and dry hay significantly increased the chance of Inflammatory Airway Disease (Mild-moderate Equine Asthma) while dust-extracted shavings and high temperature steamed hay significantly reduced the chance.
Not only is the type of bedding important, but how it is delivered, and stored can greatly affect the interior air quality. Storing both bedding and dry hay in a separate building where it doesn’t share air-space with the horses will greatly reduce the amount of dust, mould, and other allergens introduced into the air.
Forage should make up the majority of a horse’s diet and can provide between 50-100% of their energy. The amount and way in which hay is fed to stabled horses is incredibly important. When they graze in the field, they have their heads down which is their natural feeding position and allows the respiratory tract to drain, a natural defence mechanism to inhaled particles.
Plenty of hay should be fed and if the horse needs a calorie-controlled diet a slow feeder should be used to slow intake but still mean the horse has hay in front of them most of the time in order to avoid digestive complaints such as gastric ulcers.
It is therefore unavoidable that horses spend a long time with their noses in hay which even the best quality is known to contain high levels of respirable dust. High temperature steaming is the only method shown to reduce respirable dust and microbial contamination in hay and horses are found to have significantly lower incidence of IAD as a result.
Ventilation is the process by which outside air is brought into the barn where it collects and dilutes moisture, heat, and other contaminates, and exhausts them to the exterior. Effective ventilation in barn and stable designs are important and should allow for five changes of air per hour without causing a draught. Natural ventilation of the building can be achieved through stable design, but mechanical fan systems can be effective for areas of the stable where direct access to fresh air is particularly difficult.
Remove soiled bedding and droppings regularly, at least twice a day (morning and evening) if your horse is in all day but more often if possible. Activities such as this and grooming should be done when the horse is outside as this creates airborne dust.
Let There Be Light
Make sure as much natural light enters the stable as possible, keep windows and barn doors open which simultaneously helps with ventilation. Consider a stable-door chain during the day if safe to do so and if possible, install a clear plastic panel in the stable roof. Natural light is important for stimulating the production of vitamin D.
Beyond mucking out the stable, the surfaces such as windows, doors and walls should be regularly cleaned, and cobwebs removed. Sweeping or blowing areas around the stable is not recommended as this creates a lot of airborne dust and to some extent just moves it around. If this is the only option, then the horses should be well away. Hoovering walls and cobwebs is a good option and yard vacuums are also available.
Water and feed buckets should be washed out daily and disinfected weekly.
Comfort To Rest The Body
Rubber flooring provides a level of comfort and protection, the ideal flooring being padded but most importantly sealed to prevent urine getting trapped underneath which will off-gas as ammonia another harmful irritant to the respiratory system. If you can smell ammonia, then it is already at a level that will irritate the horses airways.
A Herd Of Horses
Finally, it is important to remember horses are herd animals and need the company of others to feel relaxed and secure. Being able to see other horses is very important for their mental health and when appropriate they will appreciate the ability to touch other horses.
So, in conclusion, the ideal stable environment is light and airy with clean air to save the lungs from damaging exposure to dust, a trickle feeding regime of clean forage and a clean, comfortable bed to rest and recover from exercise.
By Edzo Wisman