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


Manure is Black or Very Dark


Very dark manure may result from dietary factors such as poor nutrition. Importantly, it can also be indicative of bleeding into the upper gastrointestinal tract due to ulcers or other causes. Horses that have been treated with bismuth (Pepto Bismol) have dark manure.

Keep in mind that manure changes appearance as it dries, becoming darker over time. So this observation may also be normal. If manure is very dry and hard when first produced, it may be indicative of dehydration.

  • 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.
  • 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
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your role


What To Do

If you notice that your horse's manure is abnormally dark, that is a good starting point for additional observations.

Assess your horse's general health using the Whole Horse Exam (WHE). Pay particular attention to heart rate, general attitude, and appetite. Also assess gum color and capillary refill time. Compare the manure to that of the other horses under your care and, if possible, compare it to manure this particular horse has previously passed.

Share your findings and concerns with your vet.

your vet's role

Your vet may recommend that you save a sample of the manure for them to evaluate. In this instance, put a fecal ball or two in a ziploc bag, squeeze out the air, and put it in the refrigerator (for now) so that you can submit to your vet for evaluation.

The concern here is that there is blood in the manure causing it to appear darker than normal. With diagnostic tests, your vet can determine whether or not this is the case.

If there is black blood in the manure, it suggests that there is bleeding into the upper gastrointestinal tract (stomach or small intestine). Gastroscopy (endoscopy) is a commonly used diagnostic to examine this region of the intestine. Blood tests can help determine whether the horse has lost significant blood or not.
Questions Your Vet Might Ask:
  • Have you given the horse any medications?
  • How does the appearance of this manure differ from normal?
  • Has the horse shown signs of colic recently?
  • Do you notice other signs?
  • What is the horse's age, sex, breed and history?
  • Has the horse's feed changed recently?
  • Has the horse had colic surgery recently?
  • 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.

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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