PURULENT COLLECTIONS IN THE FRONTAL SINUS. 327 



sinus and inflammation of the mucous membrane of the frontal sinus 

 and of the horn core. These forms of inflammation frequently lead to 

 suppuration. The pus collects in the depressions and divisions of the 

 frontal or maxillary sinus. 



PURULENT COLLECTIONS IN THE FRONTAL SINUS. 



Causation. In the majority of cases inflammation of the mucous 

 membrane of the frontal sinus is produced by external causes : fractures 

 of the horns and horn core accompanied by haemorrhage into the horn 

 core ; fractures of the horn with exposure of the sinus of the horn core ; 

 wounds and violent blows on the occipital region or the frontal bone ; 

 cracks or depressions of the external wall of the sinus, etc. 



In all these cases, whether blood is effused or the mucous membrane 

 of the sinus is merely infiltrated with serum, infection may be produced 

 by germs being deposited from the air passing through the nasal cavities 

 and causing suppuration. 



Purulent collections in the frontal sinus may result from continued 

 irritation, like that due to a badly fitting yoke. They also occur as an 

 accidental complication of general diseases like gangrenous coryza. 



Symptoms. The catarrh or purulent collection in the sinus may be 

 unilateral oi** bilateral, and the symptoms vary, according to the form 

 which it assumes. 



Unilateral collections. — Nasal haemorrhage is often the first symptom, 

 but this is often regarded as of little importance, because the formation of 

 pus does not occur until very much later. The animal shows ill-defined 

 pain, loses appetite, remains dull and somnolent, and carries its head on 

 one side. The horn on the injured side is hot and sensitive, and at a 

 later stage the eye becomes affected by contiguity of tissue. It is then 

 swollen, closed, and watery ; the conjunctiva is infiltrated, and somewhat 

 inflamed. Sensibility and partial or complete dulness of the afl'ected 

 side may be detected by palpation and percussion. On the animal 

 being made to cough, a yellowish or greyish-white discharge of very 

 foetid and sometimes putrid character escapes. 



Bilateral collections. — Catarrh is rarely bilateral at first ; but if the 

 unilateral lesion is not treated, it affects the median septum dividing the 

 two cavities, and the inflammation extends to the second sinus. The 

 animal then shows dull pain, and exhibits marked depression ; sometimes 

 it appears quite prostrate. The head is carried low and inclined towards 

 the ground, while the above-mentioned ocular symptoms and the indi- 

 cations furnished by palpation and percussion extend to both sides. 

 Coughing produces momentarily a double discharge, which the animal 

 disposes of after the fashion of horned cattle. 



