What is air sac tympany?
Air sac tympany in horses is characterized by excessive accumulation of air in the air sacs. The horse's air sacs are mucosal outpouchings of the eustachian tube and are therefore part of the upper respiratory tract. In the case of air sac sympany, air can enter the air sac but cannot escape. The actual causes and the exact mechanism of development of the disease have not yet been clarified.
How does the disease manifest itself?
- soft, depressible, non-painful swelling in the gaucho region, which may be present on one or both sides ("thick cheeks"); the swelling may become progressively larger as the disease progresses
- Strained breathing and snoring as the enlarged air sacs constrict the pharynx and larynx.
- swallowing problems due to the constricted throat area, possibly also leakage of milk or other feed components from the nostrils
- clear to purulent yellow nasal discharge, cough and fever, due to increased susceptibility to secondary respiratory infections
- in severe cases, life-threatening pneumonia if milk or feed components enter the trachea and lungs due to swallowing problems
In which horses does this disease occur?
Air sac sympany is a relatively rare condition. It occurs mainly in foals and young horses up to 1 year of age, and mares are affected about 2-4 times more often than stallions. The disease is more common in the Arabian Thoroughbred, English Thoroughbred, Trotter and Quarter Horse breeds. Furthermore, air sac tympany has been found in many other breeds such as the Hanoverian, Holstein, Trakehner, Oldenburg, Paint Horse, Appaloosa, American Saddle Horse and Friesian.
How is the disease diagnosed?
Usually, the veterinarian can make a tentative diagnosis of air sac sympany based on the typical clinical symptoms. This is confirmed by an endoscopic examination of the upper respiratory tract. This involves advancing the endoscope into the air sac, which causes the congested air to be released and the typical swelling in the gaucho area to disappear. In addition, taking X-rays may be useful.
How is the disease treated?
The Clinic for Horses at the University of Veterinary Medicine Hannover has developed a minimally invasive surgical technique that does not require general anesthesia. The operation is the treatment method of choice and, according to current findings, produces very good results.