Respiration

When we are breathing, air enters the body through either the mouth or nose, travels through the muscular pharynx, or throat, down the trachea, and into the bronchial tree of the lungs until it reaches the smallest unit, a clump of alveolae. An alveola is a tiny round sac, and they occur in clumps resembling a bunch of grapes. It is here that oxygen and carbon dioxide are exchanged in the bloodstream. Oxygen is inhaled and CO2 (carbon monoxide) is exhaled. The whole process of breathing is necessary because of the exchange of these gasses.

The airways of a horse consist of the nose, throat, larynx, trachea and lungs. The content of the airways and lungs of an adult horse is 50 liter. A horse at rest inhales and exhales about 6 to 8 liters of air with each breath. A horse at rest breathes 8 to 14 times per minute. During an extremely strenuous work out this may go up to133 per minute (!!!). In canter, the number of breaths is linked to the speed of the canter.

Respiratory problems

A disorder of the airways automatically threatens the intake of oxygen and thus the overall health of your horse. When his airways are irritated, the horse will cough, possibly in combination with nasal discharge. Irritations can be the result of dust, fungi traces, infections, allergies or insufficient fresh air.
Worms can also cause coughing.

Allergies or Hypersensitivity

Allergy is an abnormally high sensitivity to certain substances, such as pollens, foods, or microorganisms. A horse is allergic when he has been bothered by sensitive airways for a longer period of time. Most probably your horse has bronchitis (a chronic cold). In that case viruses and bacteria don’t play a significant role any more. Bronchitis is chronic, and will last for the rest of his life. The muscles surrounding the airways may tense up, limiting the airflow, and in the worst-case scenario the lungs will loose their elasticity and the alveoli will burst. Eventually the horse gets “equine heaves” or “broken wind”.

What can I do?

The airways of a horse are very sensitive. It is advisable to take cautionary measures to keep the airways of your horse healthy.

• Take your horse out of his stall when you are cleaning the stall
• Pick up manure and wet spots in the stall daily
• Groom your horse in the open air
• Feed wet hay if your horse is sensitive to dust
• Moisten the concentrates with a little bit of water
• Put your horse out on pasture every day; don’t keep him in his stall day and night.
• Clean out your horse trailer before and after use.
• Worm your horse regularly
• Give your horse the necessary vaccinations on time
• An outside box stall with an upper door is preferable
• Take measures to prevent drought as much as possible.

Laryngitis

Laryngitis is an inflammation of the mucous membrane of the larynx, often caused by a viral infection or various irritations of the throat. The chronic condition may cause coughing, but mainly causes a background noise during breathing. This is very noticeable during horseback riding, when the neck of the horse is “in frame”. A yellow-white nasal discharge can occur also.

What can I do?

Alleviation of this disorder can only be reached by making the environment as dust-free as possible and by keeping the horse outside in the fresh air as much as possible (pasture, open stalls. This alleviates the irritation considerably.

Laryngeal hemiplegia or Roaring

Roaring is a disease in which one-half of the larynx becomes completely paralyzed thus the flapper and the attached vocal cord obstructs airflow when the horse inhales.
When inhaling, the airflow vibrates the paralyzed vocal cord, which causes the horse to make loud breathing noises that are described as "roaring" or "whistling." Roaring is hereditary, but can also be the cause of an inflammation or injury. The horse doesn’t experience pain.

What can I do?

There is no remedy if the cause is genetic. But because roaring can also be caused by an inflammation of the throat or injury it is important to keep a close watch when a horse is recovering from one of these illnesses. (laryngoscopical examination)

Trachea inflammation

An inflammation of the trachea or windpipe is generally caused by a viral infection and is similar to the common cold

What can I do?

Give your horse sufficient rest. Most viral infections can be treated successfully with the appropriate vaccination. Consult your veterinarian.

Bronchitis

Bronchitis is an inflammation of the bronchi, often caused by a virus infection. Neglecting to take action at the first signs may cause the bronchitis to become chronic and it may develop in asthma or broken wind (COPD =Chronic Obstructive Pulmonary Disease)
Contact your veterinarian at the first signs of an infection. Symptoms are coughing with nasal discharge or fever.

What can I do?

At the suspicion of a virus infection it is important to isolate the horse to limit the risk of contagion. Give your horse a stall with fresh air, keep your horse warm with a blanket and give him sufficient rest.

Broken wind or Chronic Obstructive Pulmonary Disease

Broken wind, also called Equine Heaves or COPD, is a chronic bronchitis: the horse has asthmatic symptoms. The airways have a chronic inflammation, which causes an excess production of mucus and swollen airways. The airways get obstructed, and the horse will have difficulty to take in sufficient oxygen. The excess mucus causes coughing.

What can I do?

Several measures can be taken to lessen the irritation. Especially fresh air and a dust-free environment will help your horse to restrain the worst irritation. Pasture is even better. His stall must be clean, preferably with free access to an outside paddock. Try to avoid molds (no straw-storage above the stall). Moisten his hay.

Contagious diseases

Influenza (the flu), rhinopneumonia (Equine herpes virus) and strangles are a number of contagious diseases. Strangles is a throat inflammation caused by bacteria. It is extremely contagious and can be passed on not only by body-to-body contact but also through the clothes or tools of caretakers. The infection starts with swollen lymph nodes of throat- and jaw and a sore throat, and the horses are reluctant to swallow. Typically the horse will stretch his neck in this phase to relieve the pain in his throat. A suppressed cough and yellowish discharge are the next signs. The horse can get a high fever
(40 – 41° Celsius, which is 104 – 105.8° Fahrenheit) and will sweat profusely.
Contact your veterinarian immediately. Eventually abscesses will affect the lymph nodes. These abscesses will ripen and ultimately burst; then recovery will be rather quick. A horse that has suffered from strangles once will almost certainly be immune for the rest of his life.

What can I do?

Always consult a veterinarian. To limit or prevent contamination, extensive hygiene measures are required. Keep the sick horse away from other horses (preferably another building) and change your clothes before you come in contact with other horses.