428 HEALTH AND DISEASE 



or disease-producing bacteria. The more common examples in the horse 

 are seen in that form of glanders termed farcy. Eecently a contagious 

 form of lymphangitis has been introduced into this country from South 

 Africa, in which specific ulceration of the skin is a leading feature of the 

 affection . 



Maladie du Coit, a venereal disease prevailing on the Continent and 

 but seldom seen in this country, ofters another example of this class of 

 ulcer. 



For particulars of these ailments, refer to them under their respective 

 headings. 



SINUS AND FISTULA 



These are narrow, more or less elongated wounds, opening on to the 

 surface by a small orifice. 



Sinuses usually communicate with an abscess, and are the channels by 

 which pus makes its escape. 



Where injury occurs to muscles, bones, or other structures, resulting in 

 suppuration, the prospect of healing after the matter has been evacuated 

 will greatly depend upon the extent to which motion can be restricted. 

 Where the part is in continued action, as occurs in the region of the 

 poll, the pus has a tendency to burrow among the muscles, and to 

 keep up tlie irritation and prevent healing; it is on this account tliat 

 what is known as " poll evil " proves so abiding and intractable an 

 ailment. 



Sinus invariably follows the long confinement of matter when formed 

 in the feet as the result of a prick; or it may arise from the lodgment of 

 some foreign substance, as a splinter of wood, in the flesh; or from the too 

 early closing of a wound before the deeper parts have healed; or from the 

 presence of a piece of dead bone in the process of sloughing, or which has 

 sloughed as the consequence of injury or disease. 



The treatment of a sinus will, of course, depend upon the cause by 

 which it was produced and is made to continue. 



Where movement is the offending factor, means must be adopted to 

 stop the action of the muscles as far as possible, and bring the part into 

 a state of rest. 



Confined pus must be evacuated either liy laying the canal freely open 

 along its entire length, or by making a counter-opening at the most de- 

 pending jjart, and allowing free drainage. All partitions in the cavity 

 to which the sinus may lead should be divided, and pockets made to 

 communicate, to facilitate the escape of pus. Where foreign bodies exist, 

 they must be removed before reparation can be hoped for. 



