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DISEASES OF JOINTS. 



Three classes of injury will be considered under this head. These 

 are, affections of the synovial sacs; those of the joint structures, or of 

 the bones and their articular surfaces, and those forms of solution of 

 continuity known as dislocations or luxations. 



Diseases of the synovial sacs. — Two forms of affection here present 

 themselves, one being the result of an abnormal secretion which . 

 induces a dropsical condition of the sac without any acute inflamma- 

 tory action, while the other is characterized by excessive inflammatory 

 symptoms, with their modifications, constituting synovitis. 



Synovial dropsies. — We have already considered in a general way 

 the presence of these peculiar oil bags in the joints, and in some regions 

 of the legs where the passage of the tendons takes place, and have 

 noticed the similarity of structure and function of both the articular 

 and the tendinous burs*, as well as the etiology of their injuries and 

 their pathological history, and we now propose to treat of the affections 

 of both. 



Windy alls. — This name is given to the dilated bursse found at the 

 posterior part of the fetlock joint. They have their origin in a drop- 

 sical condition of the bursse of the joint itself, and also of the tendon 

 which slides behind it, and are therefore further known by the des- 

 ignations of articular and tendinous. 



They appear in the form of soft and somewhat symmetrical tumors, 

 of varying dimensions, and generally well defined in their circumfer- 

 ence. They are more or less tense, according to the amount of secre- 

 tion they contain, apparently becoming softer as the foot is raised 

 and the fetlock flexed. Usually they are painless and only cause 

 lameness under certain conditions, as when they began to develop 

 themselves under the stimulus of inflammatory action, or when large 

 enough to interfere with the functions of the tendons, or again when 

 they have undergone certain pathological changes, such as calciflca- 

 tion, Avhich is among their tendencies. 



Windgalls may be attributed to external causes, such as severe 

 labor or strains resulting from heavy pulling, fast driving, or jump- 

 ing, or they may be among the sequelse of internal disorders and 

 appear as resultants of a pleuritic or pneumonic attack. 



An unnecessary amount of anxiety is sometimes experienced respect- 

 ing these growths, with much questioning touching the expediency of 

 their removal, all of which might be spared, for while they constitute 

 a blemish their uusightliness will not hinder the usefulness of the 

 animal, and in any case they rarely fail to show themselves easily 

 amenable to treatment. 



Wlien in their acute stage, and when the dropsical condition is not 

 excessive, pressure by bandages, slight alcoholic frictions, sweating, 

 the use of liniments, or perhaps a stiff blister of the ordinary kind 



