SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
Right dorsal colitis
The hypoechoic layer was less echoic than the adjacent liver. The hypoechoic layer
detected in the wall of the right dorsal colon in all horses with right dorsal colitis
appeared to correspond to submucosal edema, inflammatory cell infiltrates and
granulation tissue that was subsequently observed on post mortem examination. The
thickness of the right dorsal colon was also reported to be significantly greater than the
thickness of the right ventral colon in horses with right dorsal colitis. Thinning of the wall
of the right dorsal colon was reported in one horse treated successfully for right dorsal
colitis, as well as in one horse that experienced a rupture of the right dorsal colon. In
the treated horse that ruptured its right dorsal colon, the hypoechoic layer persisted in
spite of the decrease in wall thickness to normal. The sensitivity and specificity of the
ultrasonographic detection of right dorsal colitis remains to be determined, as does its
usefulness in monitoring the response of horses to treatment. Affected areas of the
right dorsal colon may not be accessible ultrasonographically and mural thickness may
be within the normal range in horses with severe ulceration of the right dorsal colon.
Sand enteropathy
Ultrasonography is an excellent screening tool for the detection of sand in horses.
Small, pinpoint granular hyperechoic echoes, casting multiple dirty acoustic shadows,
are imaged in the ventral most portion of the affected large intestine in horses with
sand colic, weighing down the colon and cecum and limiting its peristaltic movement.
The ventral surface of the intestine in horses with large sand accumulations is
hyperechoic and usually appears flattened. A hyperechoic band of variable thickness
with a glittery appearance has been described just deep to the mucosal surface of the
intestine. The intra-abdominal fat is often compressed by the heavy intestine. Sand was
detected ultrasonographically in nearly all horses in which moderate to large amounts
of sand had been detected radiographically. A concurrent enteropathy develops with
significant sand accumulations and is detected sonographically as thickened colonic
wall with areas of increased echogenicity. A localized peritonitis may also be present.
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