Reasons for respiratory diseases in horses
Is your horse suffering from coughing, nasal discharge, showing a loss of performance or is your horse even having difficulty breathing?
There are many reasons for this. Infectious diseases caused by pathogens such as:
- viruses
- Bacteria and
- parasites
Sensitive horses, a weakened immune system and contaminated feed promote infections. Acute respiratory diseases are often treated too late or not sufficiently, resulting in recurring infections or even chronic diseases.
These chronic, non-infectious disease courses can also trigger the same symptoms listed above.
Do not ignore the first signs
Often, horse owners only notice a little cough. When they start riding, a few small coughs can be heard. After training, some horses also have a little nasal discharge. However, these signs are often not a "little cough" and "a little nasal discharge", but the beginning of a chronic condition.
Failure to treat can have serious consequences. A "little cough" and a "bit of nasal discharge" can turn into a serious chronic problem sooner than you would like. The course of such chronic respiratory diseases varies and not every horse suffers the same. However, it is clear that your horse will not only lose a lot of performance due to permanent respiratory inflammation, but also a lot of quality of life. One of the worst cases is absolute shortness of breath, even when resting.
What can horse owners do to best support their pets with their respiratory problems?
The answer always lies in appropriate bedding and feeding management.
Since the domestication of horses, they have been dependent on humans. The former wild horse roamed the steppe in herds and consumed various plant materials there.
Today's working horse, on the other hand, stands in open, loose or box stables, mostly on the bedding we select and eats the roughage provided by humans. This type of housing and feeding inevitably exposes the horse to significantly more dust. It is now up to the horse owner to keep the horse healthy. This also includes creating an environment for the horses that is as dust-free as possible.
But here lies the crux of the matter. Since horses are so-called “continuous eaters”, meaning they are ideally busy eating for over 15 hours a day, they constantly have their noses in dusty bedding and even dustier roughage.
Hay as traditional roughage
In our latitudes, it is not possible to guarantee horses a vegetation-free winter and thus an annual pasture feed. However, humans must continue to ensure that horses are given enough roughage-rich feed. This is done by preserving the basic grass feed.
The most traditional method for this is haymaking.
However, hay is the biggest factor in the development of inflammatory processes in the respiratory tract. It is produced through the process of drying. If the drying process is inadequate, a large number of mites, bacteria and molds are produced as a by-product. Dust is also considered to be another typical problem with the product.
It has long been known that even hygienically high-quality hay contains a high concentration of microbes that are harmful to health due to the preservation process (Vandenput et al., 1997). The most frequently complained about problem by horse owners is respiratory disease (Holmquist et al., 2002). A study by CE Müller shows that the vast majority of horse owners and keepers have had negative experiences with feeding hay to their respiratory tract. This is also underlined by an analysis by Von Clausen et al., which showed back in 2004 that respiratory disease is the second most common reason for euthanizing horses.
Haylage and silage as alternatives to traditional hay?
As roughage with less dust and less microbes, haylage is, in theory, an alternative to conventional hay. Unfortunately, in practice the opposite is often the case.
An inadequate silage process or a process error can lead to microorganisms such as cloristides, enterobacteria and listerine forming in the haylage. These cause the haylage to spoil anaerobicly. This then triggers aerobic spoilage by organisms such as mold and yeast. The fermentation products and the acid content in the layers can also lead to serious illnesses. There is also the risk of botulism. This is a life-threatening poisoning caused by small animals in the preserved bales.
Gastrointestinal diseases such as colic or free stools are often associated with the feeding of haylage. Studies such as those by MJS Moore-Colyer and AC Longland demonstrate the fear that horse owners have of feeding haylage, as the vast majority have had negative experiences with feeding this roughage.
Other alleged alternatives on the way to hygienic roughage
Many horse owners and now even entire stable operators use watering of the hay to protect horses from the dust contained in the hay.
The primary purpose of this method is to bind the dust from the hay so that it no longer gets into the horses' respiratory tract. Watering also binds the dust well, but it also causes the nutrients contained in the hay to be washed out and the number of microbes to multiply enormously. An increased load of bacteria, yeasts, molds, etc. is not effective, as these also cause health-threatening problems such as diarrhea, reduced lung function, liver problems, etc.
To what extent does inhalation and food supplements help with respiratory problems?
Every horse owner fears the diagnosis of COPD, RAO, IAD. But what should you do if the vet has diagnosed it as such?
Many horse owners resort to the well-known measures such as inhalation, medication or supplements. These work well to some extent, but cannot get to the root of the problem.
It is important to eliminate the cause and not just treat the symptoms!
But how can one effectively keep the roughage at a high-quality hygienic status while binding breathable dust and killing harmful microorganisms?
The answer is unconventional and unfortunately not quite as widespread as the method of watering, namely steaming hay!
Scientific studies by renowned scientists who have been researching this field for years, such as Moore-Colyer, James, Stockdale, Leggatt and many others, show that steaming hay completely eliminates yeasts and fungi, such as the health-endangering fungus Aspergillus. In addition, the bacteria are also killed by the hot steam. The amount of respirable dust is reduced by up to 94% using this method.
The concept of steaming hay makes sense. Similar to a steamer, the nutrients are preserved. Only the NSC value (non-structural carbohydrates) drops. However, sugar and starch are not necessarily considered desirable ingredients in hay, as they can trigger insulin disorders. This imbalance in insulin production often leads to diseases such as equine metabolic syndrome (EMS), laminitis and equine polysaccharide storage myopathy (PSSM).
Steaming hay has proven to be effective not only in theory but also in practice for horses suffering from respiratory diseases. In summary, as with watering, it binds dust to a very high degree and also eliminates the harmful microbes it contains. Steaming hay can also be used successfully to treat gastrointestinal diseases caused by bacteria.
Even for horses that are only allowed to consume a small amount of water-soluble carbohydrates (WSC) and non-structural carbohydrates (NSC) due to illness, steaming hay has proven to be a suitable partner for daily roughage feeding.
Further studies on this topic:
- James, R. & Moore-Colyer, MJS [2013] Hay for horses: The nutrient content of hay before and after steam treatment in a commercial hay steamer. Proceedings of British Society of Animal Science Conference, Nottingham April 2013.
- Von Clausen, M., Preisinger, R. & Kalm, E. [2004]. Analysis of disease data in German warmblood breeding. Züchtungskunde 62 , pp. 167-178.
- Holmquist, S. & Müller, C.E. [2002]. Problems related to feeding forages to horses. Proceedings of the XIIIth International Silage Conference , pp. 152-153.
Author:
Dana Böhnke [2018]: “Influence of roughage quality and type of preservation on feed intake and acceptance in horses”.
