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


Heart Murmur Heard with Stethoscope (in Adult)


You are listening to your horse's heart and notice a hissing or whooshing sound- a heart murmur- in what you think of as an otherwise normal, healthy horse. Or your vet tells you that they hear a heart murmur when they listen to your horse's heart.

A heart murmur usually indicates either abnormal leakage of blood back through a closed valve, or relates to an area of narrowed, constricted flow during heart contraction. Interestingly, horses that are stressed or are having a bout of abdominal pain (colic) often have a transient murmur. This often disappears when the horse's primary problem is resolved.

Most murmurs in the horse are not serious and are considered within normal limits. Most disappear with a few minutes of exercise. These are known as physiologic murmurs. Your vet will likely tell you what they think of your horse's murmur.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the horse seems to be in distress.
  • 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.
You also might be observing
Very Common
Less Common
more observations

your role


What To Do

Assess your horse's general health using the Whole Horse Exam (WHE) and listen to both sides of the horse's chest. Pay special attention to your horse's gum color, capillary refill time, pulse strength and regularity, and general attitude and appetite. Trot the horse for 5-10 minutes and listen again for change in the character of the murmur. In the future, you may monitor the murmur for worsening. Ask your vet at their next visit what they think of the murmur and if other diagnostics are needed.

What Not To Do

Do not assume that this is a serious problem, without input from your vet.

your vet's role

Obviously, interpretation of a murmur and its significance is a vet's job. They will help you determine whether your horse has a physiologic murmur (within normal limits), or something pathologic and potentially serious that requires further diagnosis and possibly treatment.
Questions Your Vet Might Ask:
  • Does your horse seem normal otherwise?
  • What are the results of the Whole Horse Exam (WHE)?
  • How is your horse's attitude and appetite?
  • Have you noticed changes in exercise tolerance, i.e. breathing hard when ridden or taking a longer t
  • Does your horse still perform well and recover quickly when ridden?
  • What does the horse do for a living?

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

Author: Doug Thal DVM Dipl. ABVP