330 DISEASES OF THE HOESE. 



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 inflammatory action, while the other is 

 characterized by excessive inflammatory symptoms, with their modi- 

 fications, 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 

 bursae, as well as the etiologj^ of their injuries and their pathological 

 history, and w^e now jjropose to treat of the affections of both. 



WINDGALLS. 



This name is given to the dilated bursse found at the posterior part 

 of the fetlock joint. They have their origin in a dropsical condition 

 of the bursas of the joint itself, and also of the tendon which slides 

 behind it, and are therefore further known by the designations of 

 articular and tendinous windgalls, or puffs. (See also page 375.) 



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

 of varying dimensions, and generally Avell 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 begin to develop themselves 

 under the stimulus of inflammatory action, or when large enough to 

 interfere with the functions of the tendons, or again where they have 

 undergone certain pathological changes, such as calcification, which is 

 among their tendencies. 



Cause. — AVindgalls may be attributed to external causes, such as 

 severe labor or strains resulting from heav}^ pulling, fast driving, or 

 jumping, or they may be among the sequelae of internal disorders, 

 such as strangles or the 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 unsightliness will not hinder the usefulness of the 

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

 amenable to treatment. 



Treatment. — When in their acute stage, and when the dropsical 

 condition is not excessive, the inflammation may be checked during 



