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


Lump, Bump, Growth on Muzzle


There are a variety of lumps and bumps that can appear on a horse's muzzle. As with bumps appearing elsewhere, the possible diagnoses include traumatic swelling, wound infections, tumors, cyst, abscesses, or an inflammatory reaction to a foreign body. Gray horses can develop melanoma here. A firm bump on the side of the muzzle could also be an atheroma (false nostril cyst). Growing horses commonly have pale colored warts that suddenly appear here.

  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the results of the Whole Horse Exam (WHE) in the resting horse indicate fever (Temp>101F/38.3C), or heart rate greater than 48 BPM.
    • If the mass is large, painful or seems to be growing rapidly.
  • Code Yellow

    Contact Your Vet at Your Convenience for an Appointment
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
    • If the mass is small, non-painful or seems to be only growing slowly.

your role


What To Do

Assess the horse's general health using the Whole Horse Exam (WHE), taking note of the rectal temperature, and look and feel for bumps elsewhere.

Gently press on the bump to determine whether it feels well-defined within the tissue or blended into it, moveable within the tissue, hard or soft, painful or not. Take a photo of the bump and send it to your vet for discussion.

What Not To Do

Do not ever attempt to lance, open or drain any swelling unless advised to do so by your vet.

your vet's role

Your vet may be able to diagnose the underlying cause simply by examining a lump in this location. However, additional diagnostics may be needed to reach a definitive diagnosis.

For small bumps on the face, vets often use "excisional biopsy", meaning that we surgically remove the entire mass and then send the tissue off to the lab to reach a diagnosis. At that point, your vet may recommend any appropriate follow-up treatment.
Questions Your Vet Might Ask:
  • How old is the horse?
  • When did you first notice this?
  • When did you last think your horse seemed normal?
  • Is the mass covered with hair or not?
  • Do you notice other masses or swellings?
  • Can you tell whether the mass is painful to your horse?
  • What is the size, shape and feel of the mass?
  • Where, exactly, is it located? Can you provide a photo?
  • How large is it?
  • Has the appearance of the growths changed over time?

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
more diagnoses

Author: Doug Thal DVM Dipl. ABVP