<P> Tracheal collapse in dogs is a condition characterized by incomplete formation or weakening of the cartilaginous rings of the trachea resulting in flattening of the trachea . It can be congenital or acquired, and extrathoracic or intrathoracic (inside or outside the thoracic cavity). Tracheal collapse is a dynamic condition . Collapse of the cervical trachea or extrathoracic (in the neck) occurs during inspiration; collapse of the thoracic trachea or intrathoracic (in the chest) occurs during expiration . Tracheal collapse is most commonly found in small dog breeds, including the Chihuahua, Pomeranian, Toy Poodle, Shih Tzu, Lhasa Apso, Maltese, Pug, and Yorkshire Terrier . </P> <P> Congenital tracheal collapse appears to be caused by a deficiency of normal components of tracheal ring cartilage like glycosaminoglycans, glycoproteins, calcium, and chondroitin . Acquired tracheal collapse can be caused by Cushing's syndrome, heart disease, and chronic respiratory disease and infection . </P> <P> Symptoms include a cough (often called a "goose honk cough" due to its sound), especially when the dog is excited . This cough is usually paroxysmal in nature . Other symptoms include exercise intolerance, respiratory distress, and gagging while eating or drinking . Tracheal collapse is easily seen on a radiograph as a narrowing of the tracheal lumen . Treatment for mild to moderate cases include corticosteroids, bronchodilators, and antitussives . Medical treatment is successful in about 70 percent of tracheal collapse cases . Severe cases can be treated with surgical implantation of a tracheal stent (inside or outside of the trachea) or prosthetic rings . Extraluminal (outside the trachea) stenting is generally only used for tracheal collapse in the neck region . Intraluminal stenting has shown more promise for success with intrathoracic cases, especially using nitinol, a type of shape memory alloy composed of nickel and titanium . Potential problems include stent migration and fracture . </P>

Where is the trachea located in a dog