Page 678 - Adams and Stashak's Lameness in Horses, 7th Edition

644 Chapter 5

is not visible in most horses except when inflamed Treatment
80
or septic. This is an uncommonly reported cause of In the acute stage, synoviocentesis and the administra-
VetBooks.ir Etiology tion of corticosteroids into the bursa are recommended.
lameness.
With sufficient stall rest (6 weeks or more) and the paren-
teral administration of NSAIDs, a good end result can be
Severe adduction of the forelimb and/or the possibil- expected. Varying degrees of lameness may remain with
80
ity of direct trauma to this region is considered to be the chronic cases. Septic involvement of the bursa requires
cause (Figure 5.49). 80,99 endoscopic debridement and flushing. The initial disten-
sion of the bursa may require distension with fluid by
ultrasonographic guidance to place the needle. The bursa
Clinical Signs is small and movement of instruments is restricted by the
The involved forelimb may be held in an abducted overlying muscle and infraspinatus tendon. 99
position, presumably in an attempt to reduce the pres-
sure on the infraspinatus bursa. During exercise, a Prognosis
moderate lameness is present with an obvious In one report 3 horses returned to soundness after
decreased cranial stride. 80,99 Adduction of the limb surgical treatment of septic infraspinatus bursitis. 99
reportedly elicits a painful response and results in
increased signs of lameness at exercise (Figure 5.50).
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If the bursa is septic, the lameness exhibited is usually OSTEOCHONDROSIS (OC) OF THE
severe. 99 SCAPULOHUMERAL (SH) JOINT OR SHOULDER
Osteochondrosis (OC) of the scapulohumeral joint or
Diagnosis shoulder is most frequently diagnosed in weanlings and
Ultrasonographic evaluation and comparison with yearlings 6–12 months of age, but it has been reported
the opposite limb may be required, along with ultra- in foals younger than 5 months and in horses up to 8
sound‐guided centesis and local analgesia, for a defini- years old. 29,38,52,54,65,67,72–74 The incidence of the disease
85
tive diagnosis. 99 varies; one study reported diagnosing OC of the shoul-
der in 54 joints of 38 young horses radiographed for
shoulder problems, and in another study OC and sub-
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chondral bone cysts were observed in 6 of 29 diagnosed
shoulder problems. The condition is considered the
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most debilitating form of osteochondritis dissecans
(OCD), and when it is diagnosed in older yearlings,
IS M
chronic manifestation of secondary degenerative joint
changes is usually present. 74

IS MT

D A
ISB
C
B

IS I

Figure 5.49. This line drawing illustrates the location of the
infraspinatus bursa underlying the infraspinatus tendon. A, caudal
eminence of greater tubercle (GT); B, cranial eminence of the GT;
C, intermediate tubercle; D, lesser tubercle; ISM, infraspinatus
muscle; ISMT, musculotendinous junction of the infraspinatus
muscle; ISI, infraspinatus tendon insertion; ISB, infraspinatus bursa. Figure 5.50. Adduction of the limb may result in a painful
99
Source: Reprinted with permission from Whitcomb et al. . response in horses with infraspinatus bursitis.