1. Heat: With a clean hand, gently feel the wound and surrounding areas for excessive warmth. You may want to compare it to the same area on the opposite side of your horse.
2. Swelling: After an injury, damaged capillaries leak fluids into the surrounding soft tissues and infection-fighting cells rush to the site. This influx of healing agents is seen externally as swelling. Initial swelling in the hours after an injury is normal and usually subsides within a few days. However, if the swelling worsens or returns after waning, it may indicate infection.
To read more about why wounds are sometimes slow to heal, click here,
3. Odor: Any “off” or pungent odor coming from a wound, especially the oddly sweet smell of dead tissue, can be a sign of infection.
4. Color: Red skin adjacent to the wound can indicate infection, especially if red streaks radiate from the area outward. Keep in mind, however, that redness may be difficult to see on dark skin.
5. Exudate: Also observe the color of any exudate draining from the wound. Healthy exudate is clear or creamy—the result of natural sloughing of dead white blood cells and wound debris. On the other hand, bright green or yellow discharge indicates that an infection is at work.
6. Tenderness: Any new injury is likely to be sore. However, if your horse’s wound seems more sensitive to the touch than it was previously, or the pain has spread to the surrounding area, suspect infection.