312 



DISEASE OF THE FACIAL SINUSES. 



accumulates in the cavity and decomposes, irritating the mucous 

 membrane. This tendency to chronicity is induced by various 

 causes. 



On clinical grounds, diseases of the frontal and superior maxillary 

 sinuses must be considered together despite their varying characters 

 and causes. The following forms are recognised : — ■ 



(1) Dropsy of the sinus. A serous fluid fills one sinus or occa- 

 sionally the sinuses of both sides of the head. There may be no 

 marked change of the lining mucous membrane. 



(2) Empyema of the sinus. The sinus contains pus ; in acute 

 cases and in oxen blood may also be present. The mucous membrane 

 is thickened, vascular and covered with granulations. 



Fig. 307. — Osteornata from skull of a three year old bullock. 



(3) Tumour formation in the sinus. Carcinomata, sarcomata, 

 osteornata, odontomata, &c, may be present, accompanied by 

 varying quantities of a muco-purulent fluid. See " Tumours in the 

 Facial Sinuses and Cancer of the Superior Maxilla," in Cadiot and 

 Dollar's " Clinical Veterinary Medicine and Surgery." 



(4) Specific inflammation due to glanders, botiyomycosis, or 

 actinomycosis. Glanders ulcers and specific new growths are ac- 

 companied by a purulent fluid. 



The causes are as varied as the processes themselves. In the 

 horse the superior maxillary sinus is often involved in consequence 

 of suppurative alveolar periostitis attacking the socket of a molar 

 tooth and the discharge escaping into and infecting the cavity. It 

 may also suffer owing to the development of new growths or the 

 entrance of foreign bodies. Finally, the sinuses may become affected 



