When your horse sustains an injury that leaves an open wound, the goal is a complete and uncomplicated healing, as in the photo. A major obstacle to that goal, however, is infection. If you observe one or more of these signs of possible infection on any healing wound, consult your veterinarian.
Heat. The wound becomes warmer than the surrounding tissue.
Color. There’s reddened skin around the wound, or red streaks radiating from it.
Odor. You notice any unusual smell.
Discharge. Fluid or pus is leaking from the wound.
Swelling. Puffiness returns after the initial irritation has gone down.
Source: Kentucky Equine Research