Section II. 

 DISEASES OF THE LARYNX. 



1. Catarrh of the Larynx. Catarrhus laryngis. 



{Laryngitis catarrhalis, Angina.) 



Catarrh of the larynx develops, at least in its acute form, 

 as a superficial inflammation of the laryngeal mucosa in con- 

 nection with catarrh of the trachea (tracheal-laryngeal catarrh) ; 

 also in connection with catarrh of the pharynx (catarrh of the 

 upper respiratory passages). These affections may be con- 

 sidered under the head of laryngitis because the symptoms 

 of the latter stand in the foreground of the clinical picture. 



Etiology. One of the most common causes of acute 

 laryngeal catarrh is taking cold, hence the disease is frequently 

 seen in spring and fall. Laryngitis is also frequently due to 

 the inhalation of impure dust, or of otherwise irritating air. 

 Alcohol contained in distillery mash probably has a similar 

 effect, and cattle fattened on such mash frequently develop 

 the symptoms of acute laryngitis (so-called distillery masli 

 cough). 



Chemicals and traumatic insults maj^ likewise produce a 

 noxious effect, as for instance in sudden and awkward drench- 

 ing with fluid medicines or in the introduction of pills with a 

 stick or the removal of foreign bodies wedged in the pharynx 

 of cattle. The larynx is also irritated mechanically by long- 

 continued convulsive cough or barking or bellowing. 



A laryngitis may develop secondarily by the continuation 

 of an inflammatory process of the nose, the pharynx, the trachea, 

 the bronchi and of the lungs (catarrh, lungworm disease, 

 pneumonia, etc.). 



It is of importance that the secretions from the pharynx 

 and from the deeper respiratory tract may come in contact 

 with the larynx. Infection is frequently the cause of laryngitis 

 in a mmiber of infectious diseases (strangles, influenza, dis- 

 temper, malignant catarrhal fever, tuberculosis, glanders, etc.). 



Chronic laryngitis is produced by similar causes as those 

 which are responsible for acute larvngitis, if these causes act 



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