Q. Every time my horse gets a cut, especially on his legs, it “scars” to the point it looks like a raised wound and worse than the original injury. Is this normal? How should I manage wounds to prevent this from happening?

—Via e-mail

A. Clinically, we observe four phases of second intention wound healing—that is, healing without the use of sutures to close the wound. These include:

• The inflammatory phase. during which white blood cells enter the wound to clean it of contaminants;
• The proliferative phase, during which granulation tissue fills the wound bed;
• The contraction phase, during which the wound gets smaller circumferentially; and
• The epithelialization phase, during which new cells cross the remaining open wound bed and form a scar.

Unfortunately, in horses (but, interestingly, not ponies), the inflammatory phase can be weak and prolonged—particularly in leg wounds—leading to less-than-ideal wound healing. Other factors that may contribute to poor healing include motion at the wound site, bacterial contamination or infection, and the presence of foreign material.

A complication often encountered in leg wounds in horses is exuberant granulation tissue, or “proud flesh,” which appears as a pink to red raised mass that spills over the edges of the wound. This exuberant granulation tissue impairs both contraction and epithelialization, and a veterinarian must trim it back to within the borders of the wound bed to allow healing to progress.

A second complication that results in poor cosmetic outcomes is inadequate wound contraction, which results in more of the wound healing by epithelialization and thus a larger—sometimes raised—scar.

Wound management, particularly for large wounds, is multifactorial and will change over the course of healing to support each phase described above. Prompt cleaning and exploration to determine a wound’s full extent is a critical first step, and you might need to call your veterinarian if you’re dealing with more than a superficial cut or can’t tell how deep or severe the wound is.

If the wound is full-thickness—that is, through all layers of the skin—and your veterinarian can suture it, that’s recommended as it generally results in a more rapid and cosmetic repair. If the wound must be left open to heal, a number of wound dressings are now available to help the process. These include dressings that help remove bacterial contaminants and debris, augment the inflammatory phase, help prevent exuberant granulation tissue, and support and protect new epithelium to minimize the appearance of scarring.

Work with your veterinarian to determine the most appropriate combination of dressings and bandaging to have the best outcome for your horse’s wounds.