CHAPTER XLVIIL 



SPOEADIC DISEASES— continued. 



LOCAL DISY.AS'ES— continued. 



(I.) DISEASES OF THE EESPIEATOEY OT^GAl^S— continued. 



CEOUP— CYIf ANCHE TEACHEALIS : DIPHTHEEIA. 



CROUP. 



Young cattle, varying from a few weeks to a few montlis old, 

 are subject, when kept on low, damp pastures, more especially 

 in meadows near rivers, and during the fall of the year, to a 

 form of inflammation of the throat, characterised by the forma- 

 tion of a fibrinous exudate or false membrane of a greyish-white 

 colour, sometimes brown or yellow, extending over the larynx, 

 trachea, and sometimes fauces, or the bronchial mucous membrane. 



I have never seen this disease in any but young calves, and 

 in one district only, namely, on the borders of the Eiver Alun, 

 near Mold, Wales. Fowls are subject to croup, and Mr. James 

 Law, in the Udinhiirgh Veterinanj Review, vol. iii., page 216, 

 hints that the carnivora are subject to it. 



Croup differs from ordinary catarrhal laryngitis in a most 

 remarkable manner. In laryngitis there is an increased forma- 

 tion of mucus, which is discharged as quickly as it is formed. 

 In croup, an exudative process attends the inflammation in the 

 larynx and trachea, which induces the formation of false mem- 

 branes, varying in thickness and consistency, some of which 

 being several lines in thickness and very opaque, whilst others 

 are so thin that the mucous membrane is easily seen through 

 them. Some are so firm in consistence that they can be de- 

 tached for a considerable length without tearing, whilst others 

 are almost diffluent. In colour they vary from a dirty greyish- 



