Syuiploius. 31 



found completely filled with secretory masses. The anterior 

 wall is thin and protruding. The wall separating the large 

 from the small sinus in the horse may disappear completely. 

 If the catarrh depends on a primary disease of the teeth, one 

 generally finds, at the inner wall of the cavity, denuded rough 

 bone, or one can feel the passive motility of a tooth through 

 masses of granulation tissue. 



Symptoms. In the horse the disease usually begins with 

 the mild symptoms of a chronic unilateral nasal catarrh. There 

 is at first a mucoid, then a mucopurulent, finally a purulent 

 unilateral nasal secretion, which, in the course of time, macerates 

 the upper lip (white streak!). The amount of secretion varies 

 a good deal; it is usually increased after work and larger 

 amounts may be voided on depressing the head, but the dis- 

 charge may also cease entirely for a time. The nasal mucosa 

 appears somewhat reddened. 



An increased tenderness of the bony wall of the sinus 

 can usually be demonstrated. In severe cases increased sensi- 

 tiveness of the infra-orbital nerves may be present. 



Dullness on percussion can be shown only rarely, i. e., when 

 the catarrhal secretion or a tumor fills out a portion of the 

 sinus situated above the facial ridge, or if a tumor is connected 

 with the external wall, or if the mucosa is considerably thickened. 

 In case of a partial thinning out of the bony wall by malignant 

 tumors, the percussion sound may on the contrary be louder 

 and deeper, because the thinner bone plate produces more ex- 

 tensive vibrations. 



The percussion sound of the maxillary sinus is solely produced by the vibrations 

 of the fairly elastic bone plate and is therefore duller only in those exceptional 

 cases in which the vibrations ai-e interfered with either by a high level of fluid 

 or by a considerable increase in the thickness of the wall. 



Changes in shape are quite rare. They can at first only 

 be seen by a close comparison of the two sides of the face. 

 Later on the deformities attain such a high degree that the 

 disfiguration can already be observed at a distance. One can 

 then usually also demonstrate that the bone is thinner and 

 that it can be pressed in. Fluctuation can be shown in very 

 advanced cases, and in these the respiration may be difficult 

 and blowing. 



The sulmiaxillary lymph glands of the affected side become 

 swollen in the course of time and are changed to tough hard 

 nodules, which are not very painful or not sensitive at all 

 and not adherent either to the skin or to the bone. 



In cattle one usually observes unilateral mucoid or muco- 

 purulent, sometimes bloody, nasal discharges, occasionally 

 mixed with masses of fibrin. The infra-orbital region is tender 

 to pressure. Here there may occasionally be dullness and 



