DISEASES 0E THE RESPIRATORY SYSTEM. 87 



of the lungs, pleurae, or air passages, or due to gastric, 

 intestinal, or other abdominal irritation, occasionally 

 occurs independently of any apparent local disorder, and 

 so assumes a primary pathological importance. Although 

 it is a matter of doubt in every such case whether there 

 is not some reflex irritation at work, there are certainly 

 some instances in which previous disease or general atony 

 of the system leads to a relaxed state of the blood-vessels 

 of the laryngeal mucous membrane and chronic cough in 

 consequence. This must generally be regarded as a 

 sequela of laryngitis. It occurs most often among pam- 

 pered animals, especially when made to run about or 

 moved into the open air. They cough violently and spas- 

 modically, with a harsh, grating sound, ejecting froth 

 and mucus from the mouth. The paroxysms only occur 

 when some special cause of irritation is at work, and, 

 although the symptoms are something like those of " bone 

 in the throat," there is no impediment to the air or food 

 passages recognisable, and fits of coughing come on. 

 These cases are often of considerable duration. The 

 pathological state of the laryngeal mucous membrane 

 persists and can be only counteracted by tonics and strict 

 attention to regular exercise and feeding. Expectorants 

 prove temporarily useful, and hydrocyanic acid in doses 

 of a half to one drop is much recommended. 



Loss of the Voice, partial or complete, results tem- 

 porarily from violent prolonged barking.* The chordaa 

 vocales become relaxed and congested, and require rest 

 before they can resume their functions. It is common 

 among small excitable dogs at shows, but after the excite- 

 ment is over, if the animal be kept quiet, the voice will be 

 restored. 



Snoring is another result of a relaxed state of the 

 structures of the throat ; it depends on want of tone 

 of the velum palati, and sometimes constitutes a very 

 serious objection, as in pet dogs which sleep in their fair 

 mistress's bed-chamber. It results from pampering, and 



* Hill says, " I have also observed what may be designated a temporary or 

 simple form of laryngitis in sheep dogs when gathering flocks together," 



