A horse owner needs to be
concerned about the quality of the air in their equine establishment, and what
can be done to enhance it for the benefit of the horses and staff.
Air quality in equine establishments is important because high levels of dust and other irritants in the air are often experienced in barns and stables that do not have appropriate ventilation to combat them.
Signs of inflammatory airway disease in horses (IAD)
These can be described as follows:
- Discharge from the nose of the horse
- Wheeziness and laboured breathing
- Flared nostrils
- Below normal expected performance
- Unwillingness to exercise
It is important therefore for horse owners to put into place steps to minimise exposure to air irritants bearing in mind that horses and stable hands may spend as much as half a day in an enclosed environment.
Ingredients of stable air quality
Dust can accumulate in a stable from many sources and is analysed under the following forms according to size;
- Total dust – can be physically cleaned away and removed for the stable.
- Dust that can be inhaled – made up of smaller particles and can penetrate the upper portion of the airways. This is called thoracic dust.
- Respirable dust able to reach further into the airways – Finer dust than thoracic dust can penetrate into deeper airways and, because of its minute size, is not caught by mucus for example. Lower airways in horses are often affected by these finer particles.
- Fine and ultrafine particles – Ultrafine dust is so small it is able to infiltrate the bloodstream and cause problems in many parts of the body. There is ongoing research into this form of dust.
Combinations of all the above forms of dust exist in all equine establishments, and it may not be realised how it is contributed to by any or all of the following sources:
- Hay, bedding and unnecessary items left in the stable
- Spores of mould exist in hay, grains, tack and equipment.
- Bacteria and particles of a virus from a sick animal can contaminate the environment
- The transfer of tack and equipment, feed buckets etc can spread the existing dust particles and disease
Ammonia is also a frequent source of concern and a contributor to poor air quality. It is usually recognised by its smell, causing stinging and watery eyes. Test equipment is available to monitor the levels of ammonia present.
Decomposed urine in stable bedding will produce ammonia which will be an irritant to the respiratory airways. Ammonia levels will be nearer the floor so that horses lying down or ponies and foals are exposed to higher levels of ammonia significantly.
How stable air quality can be improved
- Ventilation – infiltrated, mechanical or natural
- Air exchange rate
Replacing stale air with fresh air is the process of ventilation, and most stables do not have a system of adequate ventilation, thereby increasing the risk of respiratory diseases.
Infiltrated ventilation occurs by air entering through gaps in the walls or floors and around doors and windows. This should not be relied upon as a completely adequate form of ventilation.
Mechanical ventilation is, as its name suggests, a form using fan equipment and a system of vents in ducts with grilles in the walls etc.
Natural ventilation can be achieved by the installation of a chimney or stack included in the roof construction. Wind blowing across the roof of the stable can help to improve the air quality, as well as the effect of air blowing from one side to the other.
The air exchange rate is an important factor to consider since no stable should experience the existence of stale air. Clearly therefore either mechanical or natural ventilation should be thought about rather than relying solely on infiltrated air.
Other factors that affect stable ventilation
Temperature and moisture differences between inside and outside conditions can affect the effectiveness of the stack system. With warm temperatures outside hot air in the stable goes out through the stack, and cooler, fresh air is drawn in through windows, doors or vents. However, in cooler temperatures, the difference between inside and outside is less and under these conditions, the stack is weaker.
Vents in eaves and ridge of the building will also improve ventilation, allowing cool, fresh air to be drawn in to replace the warm air going out through the roof. Vents along the entire ridge length are ideal to facilitate the cycle or exchange rate.
Other ways stable air quality can be improved
Basic changes to stable management can help to improve air quality. These can be listed as follows:
- Unused tack and equipment
- Barn doors open or closed
- Cleaning and sweeping
Tack and Equestrian Equipment
Try to avoid leaving equipment collecting dust in the stables. Although this only removes the visible dust, it is a good first step to dust reduction. The dust particles that are most harmful are those unseen by the eye.
The most common form of bedding is straw, but research has shown that it produces more dust than wood shavings, pellets, and shredded paper or card. It is worthwhile looking into what the market offers and new products are constantly being introduced to combat the question of dust in the stables.
Alternatives should be considered to the use of hay since studies have shown it is very much dustier than other forms of feed. Horses tend to bury their noses in the hay, especially round bales, which exposes them to increased dust levels. Consideration should be given to introducing alfalfa cubes or pellets, silage or haylage. This later is made from grass cut earlier than hay and after it is dried is wrapped in plastic to retain the nutrients contained. A recent study showed that by changing a horse’s diet to haylage can reduce dust levels dramatically.
Horse Feeding Methods
The method used to feed hay can also be detrimental to the air quality since the use of hay nets or racks can increase the particles of dust produced in contrast to hay laid on the floor. The animals head is raised to an unnatural level compared with grazing outside and causes the nose and eyes to be exposed unnecessarily. Haybar is an excellent product to minimize the impact of dust in hay as small particles are able to fall through to the floor.
However, if hay is the only viable option available, it is possible to reduce the effect of dust produced by a number of factors.
1. When you receive deliveries of hay bales, check for visible dust or mould that may have developed in transit.
2. Store hay as far away as possible from the stables, in a separate waterproof building or trailer.
3. Storage above the stalls should be avoided at all costs as it results in a constant source of dust.
Haygain Steamers are a product proven to kill pathogens and mould spores in the hay.
Leaving barn doors open or closed
Leaving the stable doors open allows fresh air to be drawn in as the warm staler air is extracted either by natural or mechanical ventilation. This will help maintain a low level of dust. It may be considered not to open the doors if the temperatures outside are lower than normal, but doing so will help to reduce dust and ammonia levels, thus providing a healthy atmosphere for the animals and stable hands.
Cleaning and sweeping the stables
When it comes to cleaning out the stalls, consider turning the horses out for exercise. Don’t move horses back into a cleaned stall for up to an hour, this gives time for any residue dust not removed to settle. Also, you may want to consider deep cleaning every stable at least once a year (some people deep clean every few months for this reason). This helps you manage dust but also combat the build-up of ammonia and ensure your stables have a high sanitary condition.
Methods of sweeping using a soft broom can be effective in removing larger particles of dust if used correctly. Also, specialised hoovers are available on the market that is able to extract the dust from the air quickly and easily.
Construction or renovation
If the owner is able to construct a new barn or range of stables or is considering the renovation of an existing establishment, particular attention should be given to the best number of vents to provide the optimum air exchange rate. An adequate number of doors, windows and roof vents are essential to maintain good air quality. Doors and windows could remain open even in colder weather and fans placed strategically can help recirculate the stable air and avoid dust to settle.
The above would make it quite clear that the question of air quality in equine establishments is very important, so as to provide a healthy working environment for the stable hands and their equine partners. It is suggested that good stable management is a worthwhile investment and will pay dividends for the owner and staff.