32 THE MANAGEMENT AND DISEASES OF THE DOG. 



seems to me that in the anatomical peculiarities of the lungs 

 in young animals we have an explanation of the fatality of the 

 disease among them. If the bronchial tubes of a young ani- 

 mal be compared with those of an adult they are seen to be 

 softer, much less rigid ; the mucous membrane is lower, not 

 so thin, nor so closely attached to the tissues beneath. Hence 

 it happens that in inflammation of the tubes from any cause, 

 swelling and tumefaction of the mucous membrane readily 

 occur, and constitute elements of danger which are directly 

 proportionate to the calibre of the tubes attacked. In the 

 cases above reported the swelling of the membrane in the lar- 

 ger tubes was considerable, and, though not sufficient to pre- 

 vent the access of air, must have interfered greatly with the 

 expulsion of mucus from the smaller tubes, not only by de- 

 creasing and narrowing the orifices of exit, but also by destroy- 

 ing, over an important area, the ciliary action so useful for 

 this purpose. The same difference is met with in human 

 practice. Ordinary acute bronchitis in the adult is not at all 

 a dangerous affection, while in young children it is the reverse ; 

 and for the very reason that in them the bronchial mucous 

 membrane swells easily, and there is not the same expulsive 

 power to enable them to get rid of the mucus which, in con- 

 sequence, accumulates, and may cause collapse or inflamma- 

 tion of the lung tissue. In- the 'lamb disease' death occurs 

 from asphyxia, caused by the collection of mucus in the tubes. 

 I have no records at hand of the state of the lung tissue in 

 these cases, whether it is in a condition of collapse or of in- 

 flammation ; probably the latter, for I see the expression 

 'verminous pneumonia,' used by some authors. 



" With reference to the pneumonic condition of the lungs 

 of the dogs in this epidemic, it will be remembered that in 

 three of \}ci& post-mortem examinations the inflammation of the 

 lungs was found without the occurrence of parasites in the 

 bronchial tubes ; the pneumonia being quite as extensive as 

 in the cases accompanied with strongyles. I must confess 

 that this circumstance has puzzled laie not a little, and I see 



