234 
INJURIES IN THE SADDLE-BED. 
The anatomy of that portion of the horse’s back carrying the saddle 
may be briefly described as follows (fig. 118) :— 
(A) In the middle line of the withers and back, under and closely 
adherent to the skin (a), lies the fascia of the dorsal panniculus (b). Below 
it extends the scapular fascia (c), which is applied closely to the termi¬ 
nation of the ligamentum nuchae, covering the superior spinous processes 
of the 5th—10th dorsal vertebrae (cl). This is not covered with muscular 
padding. 
(B) On either side of the vertebral column, in the “ saddle-bed,” or 
surface on which the saddle rests, the skin is provided with a strongly 
developed subcutis, and covers the fascia of the dorsal panniculus (b), 
which is attached by soft connective tissue to the scapula fascia (c). 
Fig. 118.—Transverse section through horse's thorax (semi-diagrammatic, after Franck). 
a, Skin ; b, fascia of panniculus ; c, scapular fascia ; d, muscular layers ; e, external fascia 
of withers ; /, muscular layers ; g, subscapular fascia. 
Below this lies a pad of muscle, comprising the latissimus and longissimus 
dorsi, the spinalis and semispinalis dorsi, the trapezius, rhomboideus 
posterior and the ilio-costalis (retractor costae) muscles. 
Injuries in the saddle-bed occur most frequently from irregularly dis¬ 
tributed pressure continued for a considerable time. Limited areas of 
skin are compressed, leading to vascular distension and rupture ; but while 
pressure continues little extravasation occurs. So soon, however, as the 
saddle is taken off, blood and lymph are passed from the ruptured vessels 
into the perivascular spaces. As in other bruises, if the skin were not 
pigmented, reddening might ha noticed. At first a serous fluid accumu¬ 
lates in the interstices of the cutaneous tissue, and at a later stage, more 
and more white corpuscles appear, with plastic infiltration. Where serious 
bruising occurs, plasma and blood are effused. The gall consists of a 
circumscribed firm swelling, not unlike that of urticaria, caused by extra¬ 
vasation into and infiltration of the cutis. It may be soft, occasionally 
