DISEASES OF THE PLEURA; PLEURISY 147 



said to occur in the tlog. Temporary dyspna?a occurs in heart disease, 

 nephritis, and some other affections. In a general sense, asthma or 

 bronchial asthma, as we designate the disease in man, is characterized 

 by attacks of acute dyspnoea at irregular intervals, caused by temporary 

 spasmodic contraction of the bronchi. While it was once generally 

 thought that asthma was a pure neurosis (bronchiale neurosum), the 

 inclination of the present clay is to believe that in the majority of cases 

 reflex action from the nasal mucous membrane is one of the chief causes. 

 The attack generally begins by constant sneezing and drawing inhala- 

 tion with great effort as if the nose was entirely filled; o-are must be taken 

 not to confuse this condition with congestion of the turbinated bones or 

 nasal polypus. 



Neo -formations of the Lung. — "With the exception of tubercular 

 alterations, changes in the lungs are exceeding rare. Carcinomas may 

 occur, generally associated with carcinoma of the thyroid or the mammary 

 glands; these appear in varying sized nodules in the lung tissue; those at- 

 tached to cartilaginous layers of the bronchi grow to quite a large size. 

 The clinical symptoms in the early stages of these formations are not very 

 pronounced and rarely observed, but may present symptoms similar 

 to chronic affections of the lungs, such as chronic bronchitis or interstitial 

 pneumonia. There may be difficulty in respiration, oedema of the head 

 and neck, due to pressure on the jugular. Frohner found one case of 

 carcinoma of the lungs where the animal had frequent hemorrhage. 

 Treatment is useless. Parascandolo, keeping up artificial respiration, 

 removed a carcinoma through the chest wall from a large dog. 



DISEASES OF THE PLEURA. 



Inflammation of the Pleura; Pleurisy. 



{Pleuritis.) 



Etiology. — The disease is divided into two forms — primary and 

 secondary pleuritis. The primary form may be caused by cold; it may 

 also occur as a metastasis, or from the presence of certain bacteria in the 

 l^lood, which find a favorable nidus in the pleura, lodge there and set up 

 pleuritis. The secondary form results from traumatic causes, such as an- 

 imal being kicked, stepped on, or receiving a violent blow on the thorax, 

 from the extension of inflammations from the surrounding organs, as 

 gangrenous pneumonia, pericarditis, or from peritonitis extendmg 

 through the diaphragm, fractured ribs, injuries to the walls of the thorax, 

 or perforation of the throat by foreign bodies. We also see it in all forms 

 of pytemia and tuberculosis. Cadeac thinks that in nine out of ten cases of 

 septicaemia following serous or fibrous pleuritis in the dog, it is of tuber- 



