Bronchitis. 187 



is favored by the nonserated state of the blood, which rapidly 

 prostrates the already weakened nervous centres. The superven- 

 tion of pneumonia will be marked by a new class of symptoms, 

 especiall}' labored breathing, dullness on percussion and crepita- 

 tion on auscultation. The susceptibility of the bowels is so great 

 in some cases of bronchitis, particularly in those associated with 

 a low fever, that superpurgation, enteritis and death may result 

 from the smallest dose of laxative medicine, — the author has seen 

 a fatal result from the administration of two drachms of aloes in 

 a case of this kind. In such circumstances the skin usually par- 

 ticipates in an equal degree, and though the superpurgation be 

 checked an extension of the disease to the feet may still prove 

 fatal or induce such changes of structure as to leave the animal 

 practically worthless. In old animals or after repeated severe 

 attacks of bronchitis it may merge into the chronic form. Thick 

 wind is a frequent sequel of severe cases from thickening or dila- 

 tation of the bronchial tubes, from collapse of the lung or from 

 emphysema. 



Post-mortem appearances. In the bodies of animals that have 

 died of bronchitis the air-passages within the lungs are filled 

 with a white or greenish yellow mucus. If this is washed from 

 the tubes by a stream of water, the mucous membrane is often 

 found to be injected, studded more or less profusely with red 

 points or with branching red lines, and with petechia, and the 

 mucous membrane is softened, sometimes thickened and friable. 

 When, however, the bronchitis has been attended by a free puru- 

 lent expectoration the mucous membrane may, when washed, 

 show no perceptible alteration from the healthy standard as ex- 

 amined by the naked eye. 



In the capillary form the blocking up of the smaller tubes by a 

 tenacious frothy mucus, and by the false membranes which form 

 complete casts of many of the tubes and the partial consolidation 

 (collapse) of circumscribed pyriform masses of lung tissue with 

 which such tubes communicate form the chief features on exami- 

 tion after death. 



This state of consolidation or collapse of lung is frequently seen 

 in simple bronchitis as well. It is then due to the blocking up of 

 one or more bronchia by plugs of tenacious mucus which act as 

 valves, preventing the entrance of air, though it may permit of 



