By Jacqui Niles, BVetMed, Cert SAS, Diplomate AVCS

The larynx (voice box) is the gate keeper at the top of the airway. It allows air into the trachea (windpipe) and down into the lungs but stops food and liquids from going down into the airways. It is made up of five cartilages which together form a box-like structure. The flow of air through the larynx is determined by the size of the opening in the middle of the larynx. When breathing in (inspiration) the laryngeal opening is dilated to allow air to move freely into the lungs, when breathing out (expiration) the laryngeal opening partially closes. During swallowing the laryngeal opening is fully closed and is covered by the epiglottis to prevent aspiration of food (breathing food down into the lungs).

WHAT IS LARYNGEAL PARALYSIS?
Any disease process which interferes with the nerve supply or function of the muscles to the larynx will prevent effective dilation of the opening of the larynx. While in > 80% of acquired laryngeal paralysis we don’t know what causes the dysfunction (idiopathic), reported causes include neck trauma (from dog fights or choke chains), masses in the neck or chest (thyroid cancer or other tumors) or trauma caused by surgery.  Read more …