CHARACTER AND COLOR OF THE MUCOUS MEMBRANES / CRT

Examining the mucous membranes of the conjunctiva and gingiva are critical parameters in the assessment of a patient presented for colic. The color of the mucous membranes in a colicky horse may vary from pale pink to brick red to cyanotic blue to purple. A colicky horse can have normal mucous membranes. Simple obstructive or spasmodic colics rarely show degenerative changes in the color or refill time of the mucous membranes. Changes in color are most likely associated with vascular strangulating lesions which cause hypovolemic changes due to fluid redistribution.

Normal mucous membranes:
Pale mucous membranes: Occurs in horses suffering from shock form hypovolemia or pain. This finding may accompany other signs such as cold extremities.
Red mucous membranes: Associated with septic or endotoxic shock when blood pools in the capillaries and small vessels.
Cyanotic mucous membranes: The result of severe or prolonged shock. This may be seen along with an overlying hyperemic tone due to the pooling of blood in the capillaries and the cell's subsequent depletion of oxygen. This indicated a poor prognostic sign and presents as a high surgical and anesthetic risk.