Air sac
Photo:Clinic for Horses of the University of Veterinary Medicine Hanover Foundation.

At the Institute of Animal Breeding and Genetics of the University of Veterinary Medicine Hanover Foundation, a research project has been ongoing for several years to elucidate air sac sympany in horses. So far, we have been able to prove that in some horse breeds a genetic component is involved in the development of air sac tympany.For further research work, however, we are dependent on the active assistance of horse owners and breeders. Therefore, we ask all owners or treating veterinarians of a horse suffering from air sac tympany to contact us.
You can support this project by providing us with blood samples or hair samples and RNA samples from affected horses and their relatives (parents, siblings or own offspring). In addition, comparison samples from healthy animals would also be helpful, which should be as unrelated as possible to diseased animals.All important information on sample collection and the required data can be found on our leaflets for blood collection, hair sample collection and RNA sample collection, which you can download on this page.
The sample material is exclusively available to the staff of the Institute of Animal Breeding and Genetics in charge of the research project. A delivery of sample material by our institute to third parties will only take place if there is an order from the owner. All data will of course be treated confidentially and used exclusively in connection with this study. All data will be anonymized, so that in case of publication of the research results no conclusion on the identity of the animal, the owner and the breeder is possible.
If you are not sure whether your horse really suffers from air sac tympany or if it is a different disease, the following information may help you.

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.

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