108 DISEASES OF THE RESPIBATOMY ORGANS. 



thing can truly be said to exist. Cough is generally absent in 

 diseases of the brain or in cases of carbonic-acid poisoning, as well 

 as in cases where the glottis and the muscles of respiration are 

 paralyzed; in such cases it is impossible to produce coughing by 

 manipulation of the throat. Dogs do not cough intentionally, but 

 if it is very painful they can suppress it. 



Au animal can be made to cough by pressing the sides of the 

 pharynx between the fingers; if the throat is pressed hard, au 

 animal will cough and make motions of the throat very similar to^ 

 those of vomiting. 



Occasionally an animal is found in whom the most severe pres- 

 sure will not produce any signs of coughing, although it may make 

 a swallowing movement. 



Several spells of coughing after a slight pressure on the pharynx 

 point to a diseased condition of that organ; if the same pressure 

 is made on the windpipe, and the animal coughs violently, it alsO' 

 indicates a diseased condition of those parts. In bronchitis and 

 catarrhal pneumonia coughing can be produced by tapping on the 

 wall of the chest. 



In the beginning of acute bronchitis and in pleurisy the cougli 

 is dull, weak, usually frequent, dry, and husky. In chronic 

 bronchitis, catarrhal or croupal pneumonia, emphysema and oedema 

 it is very much the same, but not so frequent, and in tuberculosis 

 it is hollow and dull. There are many exceptions to this rule ; 

 for instance, in cases where foreign bodies enter the lung through 

 the mouth or by vomiting, the cough is convulsive and violent, 

 resembling whooping-cough (chronic pharyngeal catarrh) in its 

 intensity. As a rule, dogs cough more frequently at night than 

 during the day. 



The expectorations cannot be examined in the dog as they are 

 in man, as the animal generally swallows all the secretions; in rare 

 instances there may be a small portion of the mucus thrown out 

 of the mouth in coughing. We can often see the animal chewing 

 or swallowing afier a fit of coughing, which indicates that the 

 animal has brought up a piece of mucus into the mouth or 

 pharynx; this is seen when the cough becomes loose, moist, or 

 rattling, and is what is termed " looseness " of the cough, being 

 seen generally in pharyngeal, tracheal, and bronchial catarrh. The 

 largest amount of excretion is seen in bronchial and tubercular 



