INFO: Inflammatory Airway Disease (IAD)

When most horse owners think of lower respiratory disease they think of serious conditions such as pneumonia or heaves. Performance horse owners, on the other hand , realize that low grade inflammation in the lower respiratory tract can cause trouble long before obvious clinical signs are apparent. A mild cough with a slight mucous discharge might mean only slight irritation, which would respond to a few days of rest—or it might be a sign of more serious trouble.

Most but not all horses with IAD have a persistent cough that lasts longer than four weeks. Coughing is not normal if it shows up consistently at the beginning of exercise, occurs spontaneously in the barn or during feeding, is deep or productive, or reduces performance in any way. Other signs of IAD that may show up less consistently include fading at the end of a race, moving the jaws or swallowing after a cough, and reluctance to collect or flex at the poll. IAD should also be considered when horses show increasing reluctance to work for no obvious reasons.

Unlike heaves, the specific cause of IAD is not known. It is most likely the result of multiple insults. Performance horses are subjected to many irritants that are present in barns, trailers, and dusty warm-up pens, in addition to facing the constant challenge of viruses and bacteria. It can be difficult to determine whether a horse has IAD or a primary infection caused by a virus or bacteria, since the symptom patterns can be very similar. Whereas viruses are rarely identified in transctracheal wash samples, bacteria commonly are; but again, in either case—viral or bacterial—we have no way of knowing whether those pathogens might have caused the inflammation or are present because of the inflammation.

Antibiotics are often prescribed based on the culture and sensitivity results for the bacteria found in the transtracheal wash sample, but it is then not uncommon for subsequent samples to reveal the presence of an entirely new bacterial infection. From a holistic viewpoint, this would suggest that bacteria are present because of the inflammation rather than the other way around, in which case the focus should be on decreasing the inflammation instead of treating an infection.

Diagnosis of IAD is based on a combination of clinical signs, the results of an endoscopic exam, transtracheal and bronchoaveolar wash results, and the horse’s response to treatment. If you suspect that you horse has IAD, you can support his respiratory tract and immune system by taking a few extra precautions such as the following.

Probiotics: Probiotics, especially acidophilus, produce substances which are antiviral and antifungal. Probiotics also support the immune system by supporting the function of the digestive system.

Decongestant Herbs: In general, herbs can be very helpful in supporting the respiratory tract. Decongestant herbs like ephedra help clear excess mucous by dilating the brochiolas. Be aware that this herb may test positive so it should not be used during competition. This herb should not be used without the guidance of an experienced herbalist.

Demulcent/Expectorant Herbs: Marshmallow, slippery elm, comfrey, mullein, and fenugreek help thin and clear out mucous.

Antispasmodic Herbs: Lobelia is an antispasmodic that can relax bronchospasms. This is a very strong herb and should not be used without the guidance of an experienced herbalist.

ImmuSun: This immune system support product from Cell Tech contains pure, whole particle beta glucan that helps with inflammation by mobilizing white blood cells to areas of injury or inflammation. These white blood cells (macrophages) remove damaged tissue quickly before it has time to trigger more inflammation.

Vitamin C and Bioflavanoids: These two supplements provide potent antioxidant benefits and support healing of the lung tissue. Citrus C/Q™ from Equilite is an especially good product that contains these antioxidants.

Tahitian Noni: Noni is a natural anti-inflammatory which is high in naturally occurring antioxidants.

Nosodes: Occasionally a certain farm will have a high incidence of IAD, which can be due to many factors including environmental irritants or resident viral, bacterial, or fungal pathogens. If this situation develops and healthy horses introduced to the farm develop symptoms, it may be valuable to make a homeopathic nosode to be given to all horses on the farm and all new horses as they are brought in. To do this, samples from a transtracheal wash are sent on ice immediately to a homeopathic pharmacy where a remedy is made based on homeopathic principles. This principle is similar to vaccination but no harmful substances are included, and the action is specific to the pathogen on a particular farm.

Antihistamines are rarely effective in treating IAD, and while antibiotics and bronchodialators may give temporary relief they do not address the underlying inflammation. Corticosteroids are the Western treatment of choice but they are palliative at best and suppress the immune system, making the horse even more susceptible to infection. Side effects of steroids also include gastrointestinal bleeding and organ damage.

You can take active steps to prevent IAD from occurring:

Bedding: Keep all bedding in the horse’s stall and trailer clean and fresh in order to avoid mold and ammonia fumes. Fine particles of manure can also be very irritating when inhaled.

Nutritional Support: Cell Tech’s Horse Matrix product is an excellent source of nutritional support because it contains probiotics, wheat sprouts, and blue-green algae. This combination is an excellent source of vitamins and minerals, and provides antioxidant support.

Tahitian Noni: Used on a regular basis, noni can stop any respiratory inflammation before it becomes problematic.

Dust Control: Keep your arena well watered and exercise your horse away from dusty warm up areas whenever possible.

Body Work: Horses must be able to breathe deeply to clear their lungs. If you horse is very muscle sore or has a fixated rib he may be breathing shallowly. In the absence of deep breathing, your horse may be unable to clear mucous and inhaled debris from the deeper airways, setting up the potential for bronchial infection and inflammation.

Contributed By: Madalyn Ward, DVM