Text © World of Showjumping
Dr. Emmanuelle Van Erck Westergren – a European specialist in equine internal medicine at Equine Sports Medicine Practice in Waterloo, Belgium – shares her knowledge on the equine respiratory system and how small changes in the daily management can have a huge impact on the horses’ overall health.
Keep it clean
Emmanuelle highlights the importance of using common sense when it comes to management of sport horses. “Many underestimate the importance of basic hygiene in the barn,” Emmanuelle says. “Simple things, such as keeping the boxes clean, will not only reduce the risk of airway problems, but will also improve the general health of your horses. If you are dealing with top level athletes, it is problematic to maintain them in boxes that are not 100% clean. We are not talking about hospital clean – but they have to be as tidy as possible in order to reduce the dust and harmful particles that will inevitably damage their lungs. Living in a dirty box will increase the risk of your horse having other conditions such as rotting hooves or skin infections and eating contaminated straw will increase the risk of your horse developing ulcers. Another aspect that needs to be considered is the people that work in the barn – it is not all about the horses. If you are asthmatic or have hay fever, you won’t be feeling too well in a dusty environment.”
If you are dealing with top level athletes, it is problematic to maintain them in boxes that are not 100% clean
“The horses’ lungs are identical to ours, only bigger,” Emmanuelle continues. “Therefore, you have to think: Would I feel comfortable spend my whole day sleeping, eating and walking in my horse’s box – would I lay down on the bedding with no hesitation? Would I breathe well – or is the air too stuffy, smelly or dusty? All these factors are really important to recognize and if you don’t feel comfortable in your horse’s box, then your horse certainly won’t either. For instance, if you can smell ammonia, it means that you are already breathing air that contains levels that are above the recommendations of the World Health Organization.”
Renew the air
“The general cleanliness is important – you have to look at the bigger picture, the whole barn,” Emmanuelle continues. “Sometimes, the horses are in older buildings that are actually not adequate for housing athletes. In a stable, the air should be renewed six times more often than in your house so it is paramount to have the air constantly recycled. Horses are very big heat- and water-producers. They have a high baseline metabolism, meaning they produce over eight litres of water during a day – simply through breathing. If there is poor ventilation and the air is not properly dried out, the moisture is going to condensate on the walls, floor and roof. Having animals inside a building increases the ambient temperature and, in combination with high moisture, this constitutes an excellent environment for both bacteria and moulds (fungus). All these germs can be harmful for horses and cause diseases, not only in the airways, but also on the skin or in the gut.”
Having a box with a window does not mean you have enough ventilation
“Having a box with a window does not mean you have enough ventilation,” Emmanuelle points out. “There needs to be a soft and constant circulation of air; not a draft, but a regular renewal with a natural entrance from the sides of the building and an evacuation of the warm air out through the roof. You can buy small thermometers that also show the level of moisture in the air; this will indicate if you have enough ventilation. The level of moisture should be maximum 70%. Any number above that – which is usual – promotes growth of pathogenic contaminants. Horses are very comfortable at a neutral temperature of ten degrees Celsius. If the temperature is above ten, they need to spend energy to cool down, and if the temperature is lower, to keep warm.”
Change in season = Good time for a big clean up
While keeping it tidy in the barn is important, how it's done also plays a role in respiratory issues. “Blowers are horrendous machines: They lift a very high load of fine particles into the air, most of which are invisible to the eye but are particularly harmful to the horses because they penetrate very deep into their airways,” Emmanuelle says. “If I could break every single blower that is out there, I would do it without any hesitation! What we also see a lot, is people sweeping the dirt and dust from the aisles of the barn straight into the boxes. Maybe it is practical to open the door and do this, but it is actually the worst thing you can do: All the dust goes in the area where the hay will be laid, increasing the burden for the horses’ airways as they eat or rest.”
Each time you have a change in season is a good time for a big clean up
“Ideally you should power wash the stables every month,” Emmanuelle continues. “But four times every year should be an absolute minimum: Each time you have a change in season is a good time for a big clean up. However, you should keep in mind that if you use strong chemical disinfectants, you can create resistances of the germs you are trying to eliminate. Some of the bacteria can develop strategies to resist the chemicals and will become impossible to eradicate. This is why we have worked on developing an alternative with Sanequine: The idea is to sow and disseminate probiotics inside the environment. The probiotics are healthy yeasts that colonize the environment and compete with harmful bacteria and fungus. When sprayed in the barn, they multiply over walls and floor, and recreate a healthy ecosystem: Horses are less exposed to pathogens and are protected, while both stable and boxes will remain cleaner and safer for longer.”
Hay and bedding; huge sources of dust and contaminants
Hay and bedding can be huge sources of dust and contaminants, Emmanuelle points out. “The hay has been collected and dried in the fields, so it is naturally contaminated with dust and particles like mould and bacteria, even with parasites, especially when summers are damp and rainy,” Emmanuelle explains. “Ideally, you would want to sanitize the hay. The cleaner and more sanitized the hay is, the healthier it is for the horse. There are several ways to do this: You can feed haylage, or use probiotics or a high temperature hay steamer. This is particularly important for horses with chronic lung disease or inflammation of the airways. “
Ideally, you would want to sanitize the hay
“A high temperature hay steamer is the most effective way of sanitizing the hay,” Emmanuelle continues. “It gets rid of all bacteria, fungi and viruses while maintaining the hay’s nutritional properties. Probiotics can also be used: They can be mixed in the water used for soaking. The probiotics multiply in the water and eradicate little particles of bacteria and fungus inside the hay. Soaking from 15 to 20 minutes is enough: Remember that when hay is soaked in water for a prolonged period of time, it will lose some of its sugars. If you have a horse with a metabolic syndrome or laminitis, soaking hay overnight can be good for eliminating excess sugars, but for an active sport horse, it can be counterproductive to eliminate some of the hay’s nutrients. Besides, scientific studies have shown that soaking hay in clear water for over 30 minutes significantly increases its content in bacterial colonies.”
“Additionally, it is important to find a way to feed the hay that is the most natural to the horse,” Emmanuelle says. “Putting the hay down on the floor is of course a solution, but the floor has to be clean. Putting the hay in a hay net or a slowfeeder/forager has to my sense two advantages: First of all, you can evaluate the quantity that you are giving more objectively. Secondly, the mesh of the net or forager challenges the horse to eat more slowly and in smaller bites, mimicking the way he eats in the wild, a way that is particularly well adapted to the stomach. Thirdly, these help keep the hay clean while allowing the horse to eat in a natural downward head position.”
Like hay, straw bedding is naturally contaminated
The bedding should also be carefully considered when creating a healthy environment for your horses. “Like hay, straw bedding is naturally contaminated,” Emmanuelle says. “Straw is not optimal for horses with respiratory problems because it is rich in both dust and biological, and often chemical, contaminants. Alternatives would be wood shavings, paper or cardboard – those are fairly easy to recycle and dust free. The advantage of dust-free wood shavings is that the wood contains natural antiseptic compounds which are going to prevent the contaminants from multiplying inside the box. Usually, shavings are cleaner and more hygienic than straw. If they are comfortable enough, thick rubber mats on the floor in the boxes can also help keep the levels of dust lower when the amount of bedding can be reduced. However, a drawback with rubber mats that are not melted over the floor and cleaned daily, is that urine, faeces and grunge can accumulate under the mats and cause dramatic increase in bacteria levels. Cornell University in the US has tested a dense rubber mat and foam flooring system that is fully sealed to the floor and both comfortable and hygienic, reducing the amount of bedding required for the horse to feel snug.”
Lack of energy is the first symptom of respiratory issues
When looking for symptoms of respiratory issues, Emmanuelle explains that the first signs of anything going on wrong in the lungs – i.e. in the deep parts of the airways – is lack of energy. “If you have a horse that feels tired, takes longer time to recover, feels heavy to work – instead of changing the food or adding vitamins – you should first consider it could be a respiratory issue,” Emmanuelle says. “This can happen without classical symptoms like coughing or discharge from the nose”.
“A healthy horse should never cough!” Emmanuelle continues. “Cough is really a protective reflex: If the horse is coughing, it means there is something bothering it – either the horse is inhaling dust and tries to clear the airways, or it has mucus that is coming up from the lower airways. Cough always means that there is something either coming in or getting out. It can also be a sign of inflammation of the airways. It is not necessary to call a vet immediately, but you should go through a little check list: Could there be too much dust in the stable, is the bedding contaminated, am I riding on a dusty surface?”
A healthy horse should never cough
“As a rider you should also keep an eye on what happens after work,” Emmanuelle continues. “If you have got a lot of white stuff at the rim of your horse’s nose after riding, the colour indicates that you have inflammatory proteins mixed with the natural liquids of your horse, which can be a sign of an infection. Transparent liquid is fine, but as soon as it turns white, fluffy or thick – if you put your finger along your horse’s nose and it feels sticky – it means the horse is reacting against something.”
Coughing in the beginning of an exercise differs from a cough later on, Emmanuelle explains. “When a horse coughs at the beginning of work, it usually means that it is clearing mucus that is in the upper airways. If a horse coughs in the middle, or at the end, of an exercise, it usually means that there is something going on deeper in the airways. It can be a sign of ongoing chronic inflammation – horses that cough at the end of a course or a strenuous training session, are horses that could be bleeding from their lungs. Those are horses that are prone to having what we call exercise induced pulmonary haemorrhage (EIPH). It is a well-known issue among racehorses, but it also happens in show jumping. It is related to the intensity of the exercise, and often to co-existing inflammation. Sometimes the blood comes out of the nose, taking 30 minutes to two hours after the jumping to come out, but the blood can also stay in the airways. Hence, if you have a horse that coughs recurrently, I encourage you to at least ask a vet to listen to your horse’s lungs. However, it is sometimes hard for a vet to detect what is going on in the thorax of a horse, because it is a very large cavity and you are trying to listen to subtle sounds. Therefore, even if a vet does not hear anything special, but you have worrisome symptoms, it is a good idea to have him or her take a closer look by doing additional examinations.”
Assessing the airways
There are two ways of assessing the airways, Emmanuelle explains. “Endoscopy – going inside the airways with a camera – is an easy way of checking your horse’s airways,” she tells. “If you have the impression that there is something going on deeper in the airways, you can do a BAL or broncho-alveolar lavage: A limited amount of fluid is instilled inside the lungs and, when retrieved, is mixed with cells that come from the deeper parts of the airways. When analysed under a microscope, these can give an idea of the type of inflammatory process that goes on inside the lungs – if any – and what type and amount of particles the horse has been inhaling. It tells you if the horse is allergic, if it has asthma, if there is an infection – it yields a lot information. To me, it is one of the most useful examinations to plan when you suspect your horse has an airway issue. All these examinations can be done at home. For chest X-rays you need a clinic, but it is not the first thing to do when investigating a horse with respiratory issues – unlike what is done in humans.”
Sometimes, just a simple change in the environment can be life-changing for the horse
“Once we have the whole picture, it is important not to just medicate but also to think about how to better manage the horse and his environment,” Emmanuelle says about solving respiratory issues. “Sometimes, just a simple change in the environment can be life-changing for the horse. If the horse is sensitive, it can be riding earlier in the day when there is more moisture in the air and less dust, it can be changing the bedding or the way you feed the hay, it can be the way you store the hay… If you store the hay above or next to the horses, it more likely will cause problems.”
Preventing problems is easier than trying to solve them
Preventing problems is easier than trying to solve them – and Emmanuelle believes that inhalators or nebulizers are a good way of keeping the horses’ airways clean. “It does not necessarily mean that you should put medication in it all the time though: You can use very simple products such as saline – which is just lightly salted water,” she explains. “This helps to clear out the airways and makes the mucus more fluid. The risk of infection increases when going to a show, where your horse is going to be in contact with other horses. Additionally, we know that transport and competitions can cause physiological stress to the horses’ immunity. Therefore, if you have a horse that has had respiratory problems, using an inhalator is a good way of preventing their recurrence. It is usually a good idea to use the inhalator prior to exercise, as it helps the horse to breathe better while exercising.”
“If people have the perception that all of this is a lot of work – it is much more work taking a horse to a vet and it is more expensive to pay for the medication than to adopt simple things and review barn management,” Emmanuelle concludes.
*Dr Emmanuelle Van Erck Westergren is the president of the Belgian Equine Practitioner Society (BEPS). She graduated from the Ecole Nationale Vétérinaire de Maison Alfort (France) and did a PhD on respiratory functional tests in horses at the University of Liege (Belgium). She is a diplomate of the European College of Equine Internal Medicine (ECEIM). Emmanuelle founded her specialized referral practice, the Equine Sports Medicine Practice based in Belgium and consults internationally.
No reproduction without written permission, copyright © World of Showjumping.com