An inflammation of the voice box or larynx is called laryngitis. The usual cause of this condition is a microbial infection in the upper respiratory tract. Irritation of the larynx caused by inhaling smoke, dust or toxic gases may result in laryngitis. Strain resulting from excessive barking and physical injury caused to the voice box while inserting a breathing tube during surgery are other reasons for laryngitis in dogs. Infectious diseases such as canine distemper and tracheobronchitis also may cause this condition. Overexcitement resulting in continuous panting and additional respiratory effort required in the case of paralysis affecting larynx are some of the other reasons. Dog breeds such as pugs that have short noses and flattened faces are more prone to laryngitis. Obesity in dogs may predispose them to this condition too.
Laryngitis often begins with a dry, harsh cough which later develops into productive cough that is painful. Bouts of coughing may be triggered by dusty air, cold water and air, coarse food and attempts at giving medicines to the dog. Accumulation of fluid in the larynx and inflammation of the mucous membranes are two of the usual symptoms of laryngitis. Obstruction of the upper respiratory tract may occur in severe cases. Change is voice may be pronounced. Difficulty in breathing accompanied by bad breath is common. The dog may hang its head down, keeping the mouth open. Pain and difficulty in swallowing food also may be present. When laryngitis is associated with paralysis, the dog may die due to suffocation, especially if it is subjected to overexertion, but it is a rare occurrence. .
Inflammation and fluid retention in the larynx may take place rapidly, causing the dog to breathe laboriously and with a high-pitched noise. Due to the decrease in the respiratory rate resulting from the additional effort required to breathe, the oxygenation of blood steadily decreases. The mucous membranes turn blue because of low oxygen levels in the blood. Increase in temperature and pulse rate may be observed. Obstruction of the airways may render panting ineffective in cooling the dog in hot weather, raising its body temperature considerably. Severe obstruction may lead to collapse if medical attention is not given.
The typical symptoms displayed by the dog may help the veterinarian to diagnose the condition. However, endoscopic examination of the respiratory tract may be necessary to confirm laryngitis. The dog may have to be anesthetized for conducting this examination. Obstruction of the larynx may necessitate a surgical procedure to make a temporary opening in the dog’s neck through which a tracheotomy tube is passed. This tube allows the passage of air to and fro from the lungs while laryngitis is being treated.
To start with, the cause of laryngitis should be determined and treated accordingly. Antibiotics and anti-inflammatory medications, including both non-steroidal drugs and corticosteroids, are administered to treat the infection and to reduce the obstruction due to swelling. Cough suppressants and antihistamines to treat allergic reactions are also given. Diuretics may help reduce fluid collection in the lungs and the larynx. Keeping the dog in a clean, warm, and dust-free environment with increased humidity may accelerate recovery. The dog may require liquid foods during the treatment period.