328 NASAL CAVITIES. 



Diagnosis. The diagnosis only presents difficulty in the early stages. 

 Later the warmth and sensitiveness of the horns, the j^artial dulness, 

 offensive character of the discharge, etc., render diagnosis easy. 



The disease is not likely to be mistaken for gangrenous coryza, 

 despite the condition of the eyes, because it develops slowly, progres- 

 sively, and without marked fever. 



Prognosis. If treated early, unilateral or bilateral collections of pus 

 in the sinuses are capable of cure, but later when bodily health is im- 

 paired and the local lesions of the mucous membrane very pronounced, 

 there is less chance of success. 



Lesions. The initial lesions consist in cracks, fissures, or fractures 

 of the bones of the face or exostoses of traumatic origin. In other cases 

 the mucous membrane alone is affected. As a result of chronic irrita- 

 tion it becomes thickened, inflamed, and ulcerated, and granulates 

 freely. The depressions in the sinuses contain grumous, foetid pus, 

 which irritates the surrounding tissues and produces pain and general 

 symj^toms of cerebral irritation, which are sometimes very disquieting. 



Treatment. Numerous methods of treatment were formerly recom- 

 mended, such as absolute rest, bleeding, cold affusions, perforation of a 

 horn, section of a horn, etc. None of these is of any value. 



At first, provided only a certain degree of sensitiveness and simple 

 catarrh without suppuration exist, antiseptic fumigations \fith tar, car- 

 bolic acid, thymol, etc., are useful ; but later, when pus has formed, 

 they are useless. At this period the only rational and efficacious treat- 

 ment consists in trepanation. In unilateral collections three openings 

 are necessary. 



The first is an opening into the sinus of the horn core. It is made 

 I to f of an inch above the horn-secreting band of the horn. It must 

 not be forgotten, however, in planning such an opening that the sinus of 

 the horn core only exists in a rudimentary condition in young animals, 

 and that it is scarcely possible to trephine the horns before the patient 

 is three years of age. 



The second opening is made towards the upper part of the frontal 

 sinus about f inch below the horn-secreting ring at the base of the 

 horn and in a line with the axis of the horn core itself. Whatever the 

 animal's, age and however little the sinuses may be developed, this 

 opening is certain to expose the cavity of the frontal sinus. 



In old animals where the frontal sinus is enormously developed, and 

 where very large depressions exist in the orbital region, a third opening 

 should be made just above a transverse line uniting the upper margins 

 of the two orbits and inside the suborbital suture. 



These openings having been made, treatment consists — firstly, in 

 completely washing out the cavity with boiled water, cooled to 95° or 



