TREATMENT OF STERNAL SINUS. 477 



by the heels of a fore-shoe, by kicks, punctured wounds, or in stallions, 

 by bruising the breast when covering. The bone is either directly 

 injured, ostitis and necrosis resulting, or it is indirectly affected from 

 cellulitis extending to it from the neighbouring textures. The thick 

 muscular covering of the breast bone renders the removal of any 

 necrotic portions difficult and tedious ; infection meanwhile extends 

 and new necrotic centres are formed, thus protracting the process 

 for months or indefinitely. Frequently the sinus shows only a small 

 opening from which a thick straw-coloured fluid is discharged in 

 varying quantity. From time to time, abscesses form, and when 

 these have been evacuated, the inflammatory process appears to 

 subside, leaving considerable substernal swelling which gradually 

 undergoes induration ; the inflammation then either disappears or 

 the substernal thickening becomes greater. 



Brill described a sternal sinus with two openings below and three 

 at the height of the costal cartilages in a colt 2£ years old. Similar 

 conditions have occasionally been seen in cattle. Delle mentions 

 that a cow swallowed a splinter of glass, which perforated the rumen 

 and lower wall of the chest, and produced sternal abscess and sinus. 

 The glass was removed, and recovery occurred in five months. 



Symptoms. A semi-soft, slightly painful swelling appears between 

 the fore-limbs, sometimes exhibiting sinuous openings, from one or 

 several of which offensive pus discharges. A probe introduced far 

 enough strikes on the roughened surface of the necrotic bone. In 

 other cases the chief symptom is substernal cedematous, slightly 

 painful swelling, with at some point a small wound, more or less 

 concealed by the sticky discharge which mats the hair forming a 

 crust over the sinus. Occasionally the swelling interferes with 

 movement of the fore-limbs, causing lameness or a straddling gait. 



The Prognosis is unfavourable, though the disease is more dis- 

 figuring than deadly ; occasionally, however, infection extends to 

 the pleura, producing a fatal result. If treatment be attempted, 

 it should be of an experimental character, and based on general 

 principles. Many practitioners confine their efforts to dealing with 

 the attacks of cellulitis. 



Treatment. The disease is always chronic, recovery rare. Laying 

 the parts open, removing necrotic portions of the sternum, careful 

 disinfection, followed by the use of iodoform and other antiseptics, 

 have usually been found useless. Giinther testifies to the inveteracy 

 of the disease. It is seldom worth while to carry out a tiresome, 

 costly, and rarely effectual treatment. Isolated recoveries may, 

 however, occur. The sinus may be favourably situated for efficient 



