Small Airway Inflammatory Disease in Horses

December 18, 2006 (published)

Today on the program I am going to discuss a chronic lung disease of horses called small airway inflammatory disease, or SAID. This is not a contagious disease but a disease that in the first stages causes exercise intolerance. You may feel your horse is just not as responsive as in the past when being worked. Maybe he doesn't seem to have the energy and appears to be slowing down. This problem develops gradually, and the hotter the temperature the more affected the horse seems to be. Also, an intermittent deep cough may be noted due to excessive mucous in the airways. The difference between this syndrome and an infectious disease is that infectious diseases are usually acute and the horse usually feels bad and may stop eating, which does not generally occur with SAID.

The cause of SAID is related to allergens and many horses are more affected in the spring and summer because of more allergens and the heat at the same time. However, many horses also develop this syndrome in the winter as they are stalled in barns because of the weather and exposed to dust and other allergens. Dust in a horse stall contains molds, bacteria, fungi, ammonia, and other chemicals that are harmful to the airways. These particles are trapped inside the airways and cause inflammation and some horses are more sensitive to these particles than others, and more severely affected horses develop a condition called heaves. Diagnosis of the condition is made by placing a tube in the lung and retrieving fluid for analysis, a process called a bronchoalveolar lavage. Treatment of the disease involves bronchodilators, anti-inflammatories, and maybe most important of all, environmental management changes. Join us on our next program for specifics on treatment.

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