What you see. The starting point for addressing any equine health related issue is your observation.


Healing Leg Wound, Sudden Increase in Swelling, Drainage or Lameness


You have been treating your horse's leg wound for a period of time, hopefully with veterinary guidance. The wound is getting smaller and seeming to heal well. But one day you suddenly notice increased swelling, or sudden onset of lameness. What might this mean?

Normal skin is covered in bacteria. Healing wounds are covered in bacteria. Cleaning a wound temporarily reduces the bacterial population but it does not rid the wound bed of bacteria, and the bacterial population rapidly returns. This is ok, because a normal bacterial population is an expected part of the healing process. Antibiotics change this bacterial population but certainly do not rid the wound of bacteria.

However, sometimes normal bacteria can colonize the deeper part of the wound, and create a closed infection, either under the skin or within the tissues. Since it cannot drain, it swells resulting in an abscess.

Worse yet, during healing, suddenly bacteria might gain access to a tendon sheath or joint. In most cases, swelling and lameness will result.

In other cases, abnormal or "bad" pathogenic bacteria can create a significant wound infection, which causes inflammation, swelling and lameness.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If severe lameness accompanies this sign.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If there is modest or little lameness but significant swelling.
You also might be observing
Very Common
Less Common
more observations

your role


What To Do

Assess the horse's general health using the Whole Horse Exam (WHE) and assess the horse for lameness. If the horse is severely lame, contact your veterinarian immediately.

Clean the wound well. Look for obvious changes in the wound's appearance and send a photo to your vet for discussion.

What Not To Do

Do not EVER continue to treat a leg wound in a horse that is (or has suddenly become) very lame, without veterinary guidance. You risk the life of your horse because it is likely that a joint or tendon sheath is involved and is the cause of the lameness.

your vet's role

Your vet will examine the wound and use various diagnostics to determine what has happened. It will most likely be one of the three conditions described above.
Questions Your Vet Might Ask:
  • Has lameness increased with time?
  • Is there any drainage?
  • Has swelling increased?
  • Has drainage from the wound increased or decreased?
  • How have you been treating the wound?
  • How lame does the horse seem to you?
  • Where is the swelling specifically- front, back, side?
  • Tell me more about the color, smell, and quantity of the drainage.
  • Do you notice odor to the drainage or wound?
  • Can you send a photo of the problem?
  • How aggressive do you want to be in treating this?
  • What are the results of the Whole Horse Exam (WHE)?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
Less Common
more diagnoses

further reading & resources

Author: Doug Thal DVM Dipl. ABVP