With very fit horses, it may be difficult to see any movement of the rib cage or of the flank because they are breathing so effortlessly. In this case, you may find it easier to watch the movement of the nostrils to get the rate. Normal respiratory rate is 12 to 20 breaths per minute. With your pen light, look at the gums by carefully lifting up the upper lip. Normal color is pearly pink.
Abnormal color can be pale, dark pink, red, or bluish.
The gums should be moist. Normal CRT is less than one second. Skin turgidity or elasticity is a method to evaluate hydration status. It is checked by tenting the skin up near the base of the shoulder, releasing it, and watching how fast it bounces back - it should bounce back instantly. Whatever the nature of the problem, whether it is illness, lameness, wound, hemorrhage, colic, or something you're not sure of, the vital signs are important in determining how serious the horse's general condition is.