CAPPED ELBOW IN THE HORSE. 
531 
produces excessive pain on movement. The patient may sustain weight 
on the limb, but carefully avoids any movement of the joint, particularly 
at the commencement, when acute synovitis alone exists. Afterwards 
fever and marked swelling of the whole joint set in. 
The course is almost always unfavourable, acute inflammation of this 
joint often ending fatally, and chronic inflammation being followed by 
incurable lameness. 
Treatment is, therefore, chiefly of a prophylactic character, and follows 
general principles, including careful antisepsis of wounds involving the 
joint or tendon sheath above mentioned. In suppuration involving the 
joint, little can be done. The thick muscular tissue and unyielding 
capsular ligament present great difficulties to washing out the cavity, 
and usually render such treatment useless. The form of arthritis 
chronica seen by Percival was also incurable, and, after long and 
unsuccessful treatment, the horse was killed. 
CAPPED ELBOW IN THE HORSE. 
The structure corresponding to the bursa olecrani of man is found in 
the horse and dog at the posterior surface of the elbow-joint, and though 
not constant, generally forms below the skin a bursa mucosa as large as 
a walnut or apple. Injury caused by the heel of the shoe may result 
in local infection (discomyces) and produce a swelling, vulgarly termed 
“ capped elbow.” 
Pathological anatomy. Bruising leads to acute inflammation of 
the bursa ; sometimes bleeding takes place into the bursal cavity; some¬ 
times bursitis sero-fibrinosa vel hgemorrhagica occurs. If pus cocci 
enter, bursitis suppurativa may result. In any case, however, the con¬ 
nective tissue around the joint also suffers (parabursitis), though in the 
horse this condition is not marked. At first, oedematous swelling of the 
connective tissues sets in, but later gives place to plastic infiltration, and 
finally to extensive formation of fresh connective tissue, which may even 
become ossified. 
The disease, therefore, consists of a bursitis and parabursitis olecrani. 
The swelling is chiefly caused by the latter. 
Symptoms. The clinical symptoms differ somewhat according to the 
pathological changes. The only constant feature is the swelling, which 
is more or less sharply differentiated from its surroundings. When 
recent, it feels abnormally warm, is doughy and slightly painful. It 
afterwards becomes harder, depending on the degree of plastic infiltra¬ 
tion and induration of para bursal tissue. Occasionally distension of the 
bursa is the more prominent symptom, and the swelling is then 
fluctuating, and on being opened discharges blood-stained fluid. The 
bursa may become as large as a man’s fist and contain fibrinous clots. 
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