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


Membranes of Mouth, Gums appear Dark


There are a few areas on the body that provide important information regarding the state of a horse's circulatory health. These areas include the gums, the pink membrane inside the nostril, the whites of the eyes, and the pink inner vulvar membranes of mares. That said, the simple act of evaluating the color of your horse's gums is actually a very important skill for better understanding your horse.

Dark mucous membranes can indicate a variety of disease processes. Horses that are dehydrated often have dark-appearing gums and slow refill times. When examining horses with darkly pigmented gums, keep in mind that some horses (especially dark bay colored) have areas of their gums which are darkly pigmented. This pigment can change the appearance of the gums and make them hard to interpret. Occasionally, horses will eat substances that stain the gums. This is especially common in grazing horses.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the results of the Whole Horse Exam (WHE) indicate fever (Temp>101F/38.3C), or heart rate greater than 48 BPM that persists an hour after recovery from exercise.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the horse's appetite and attitude are normal and you see nothing else wrong.
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
You also might be observing
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your role


What To Do

Reexamine your horse's gums in different light. Always check both sides of the mouth if you think your horse's gums are a strange color. Wipe the gums clean with a moist paper towel if you have any doubt, and then recheck the appearance. There may be material on the gums that is confusing your interpretation. Check the appearance of the whites of the eyes, and if the horse is a mare, check the vulvar mucous membrane color for comparison.

When in doubt, assess your horse's general health using the Whole Horse Exam (WHE), paying particular attention to capillary refill time (CRT) and heart rate and general attitude. Look for other signs of illness or disease. Call your vet to discuss your concerns.

your vet's role

Your vet may advise you to take a "wait and see" approach or suggest that they examine your horse. Much of this will depend on history and the presence or absence of other concerning signs. Your vet will assess your horse's general health with a physical examination, and try to determine the nature of the finding. Vets are experts at interpreting the appearance of gums because they do it all the time. Blood work may provide additional important information.
Questions Your Vet Might Ask:
  • Does the horse appear normal other than this finding?
  • Have you looked at both sides of the horse and accounted for different light?
  • Does the horse's attitude and appetite seem normal?
  • What are the results of the Whole Horse Exam (WHE)?
  • Have you compared the appearance in this horse to that in your other horses?

Diagnoses Your Vet May Consider

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

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Treatments Your Vet May Recommend

A way to resolve the condition or diagnosis. Resolving the underlying cause or treating the signs of disease (symptomatic treatment)

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Author: Doug Thal DVM Dipl. ABVP