Diseases of the Respiratory System

Chapter 35 Diseases of the Respiratory System


The respiratory system of birds is uniquely designed for flight. The nostrils are found in the cere, the area around the most dorsal surface of the upper beak. The cere of male budgies is usually blue, whereas in females it is pink. Discoloration of the cere may indicate gonadal tumors in budgerigars. The nasal cavity is divided by a septum. An infraorbital sinus is located ventromedial to the orbit of the eye—this is the site of swellings involved in sinusitis. The glottis (the opening to the trachea) is located on the dorsum of the tongue and is not covered by an epiglottis. The trachea bifurcates immediately after the thoracic inlet, and the bifurcation is the location of the syrinx, the voice box of birds. The lungs are paired and are firmly attached to the dorsal body wall.


Birds do not have a diaphragm, thus they must be able to expand their chest wall to breathe (be careful not to impede chest movements during restraint procedures). Birds have a series of air sacs that are connected to the lungs. The air sacs are thin-walled structures that extend throughout body cavities and into the pneumatic wing and leg bones. Most birds have two cervical, two anterior thoracic, two posterior thoracic, two abdominal, and one interclavicular air sac. The air sacs make possible the continuous flow of oxygen to the lungs. With each breath, the bird replaces 50% of the air in the lungs with fresh air—fresh air enters the lungs on both expiration and inspiration. This highly efficient system allows for oxygen transport throughout the body even at high altitudes seen in flight.


Respiratory problems are frequently seen in pet birds. The design of the respiratory system predisposes birds to these problems. Bacterial, viral, and mycotic causes of respiratory symptoms are addressed in Chapter 34. This chapter deals with diseases that are specific to structures in the respiratory system: the nasal cavity, sinuses, trachea, syrinx, lungs, and air sacs.




Rhinitis


Nasal discharge seen in birds may vary from clear to opaque, yellow mucus. It is usually the result of infection or irritation to the nasal cavity. Birds on a poor diet or those housed in dry environments may experience development of nasal plugs, that is, concretions of dust and debris that block the openings to the nares.





Aug 31, 2016 | Posted by in GENERAL | Comments Off on Diseases of the Respiratory System

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