ETIOLOGY AND OCCURRENCE 27 



some instances the condition is recurrent. Each attack is of 

 long-er duration, and eventually death results from continued 

 suffering, emaciation and intoxication. 



AFFECTIONS OF BURSAE AND THECAE. 



Acute bursitis and thecitis is of fre(|uent occurrence in horses 

 ])ecause of direct injury from contusion, punctures and other 

 forms of traumatism. These synovial membranes, with few ex- 

 ceptions, when inflamed occasion a synovitis that may be very 

 acute, yet there is less manifestation of pain than in arthritis. 



It is only in structures such as the bursa intertubercularis or 

 in the sheath of the deep digital flexor that an inflammation 

 causes much pain and is apt to result in permanent lameness. 

 This is due to the i^eculiar character of the function of such 

 structures. 



An acute inflammation of a small bursa may even result in the 

 destruction of such synovial apparatus without serious incon- 

 venience to the subject, either at the time of destruction or there- 

 after. Obliteration of the superficial bursa over the summit of 

 the OS calcis is not likely to cause serious inconvenience or distress 

 to the subject unless it be due to an infected wound. Even then, 

 with reasonably good care given the animal, recovery is almost 

 certain. Complete return of function of the member and cessa- 

 tion of lameness takes place within a few weeks in the average 

 case. 



"Where an infectious synovitis involves a structure such as the 

 sheath of the tendon of the deep digital flexor (perforans) the 

 condition is grave and because of the location of this theca the 

 prognosis is not much more favorable than in an articular syn- 

 ovitis. 



Inflammation of bursae and thecae may be classified on a 

 chronological basis with propriety 1)ecause the duration of such 

 affections, in many cases, materially modifies the result. A 

 chronic inflammatory involvement of a theca through which an 

 important tendon plays may cause adhesions to form. Or there 

 may occur erosions of the parts with eventual hypoi-fi-ophy and 

 loss of function, partial or complete. 



However, in general practice a classiflcation on an etiological 



