What Your Horse’s Manure Tells You

Your horse’s digestive health is critical to their overall well-being and performance. While we often think of manure as just a by-product of digestion, it can be a good indicator of your horse’s digestive and overall health. The characteristics of horse manure can indicate important information on your horse’s diet and any underlying health problems. Thus, while inspecting your horse’s manure may not be the most fun task, it should be done daily.

Features of Horse Manure that Mean Something

There are many characteristics of horse manure that can indicate either if a horse is healthy or may be suffering from an illness. It can also help identify any dietary issues or digestive upset, or even risks or signs of colic. Some general guidelines when inspecting horse manure would include:

• Consistency and appearance. How the manure of a horse looks and even feels are primary indicators of how well a horse’s digestive system is operating and their overall health. Healthy horse manure is generally well-formed into fecal balls. It should appear moist and easily breakable. If the fecal balls are hard and dry, it can be an indicator the horse is either dehydrated or is lacking fiber in their diet. Conversely, loose, and watery manure would be categorized as diarrhea. There are a number of causes of diarrhea.
• Color. The color of a horse’s manure can tell you much about their diet and how well they are digesting their feed.
  1. Brown-colored manure is usually considered the normal color of most healthy horses. It is usually a good indicator that the horse’s digestive system is functioning properly. It also suggests a well-balanced diet with sufficient absorption of nutrients.
  2. Green-colored manure often indicates there is undigested plant material. This is usually observed when horses are eating fresh or lush pastures. It can also be seen in hays with a high chlorophyll content, like alfalfa. Usually, green colored manure is not a concern, but if seen with other abnormalities (i.e., diarrhea), it can indicate digestive upset or other issues.
  3. Black or very-dark colored manure can be an indicator of gastrointestinal bleeding. The reason it is usually dark or black is because of the digestion of blood. This could be an indication of severe gastric ulcers or other causes of bleeding in the digestive tract, and will require immediate veterinary care.
  4. Red or bloody-colored manure would indicate bleeding in the hindgut of the horse. The blood had not yet been digested and thus, is still red. This could be caused by colitis, parasites, or even rectal tears. Again, this would require immediate veterinary care.
  5. Yellow-colored manure can be a sign of liver dysfunction or excessive bile production. This would be an indication the horse is having difficulty digesting the fats in its diet. Alternatively, horses on high fat or high NSC (grain) diets may have a yellowish tinge to their manure. If other symptoms, like lethargy or changes in behavior exist, it would be advisable to contact your veterinarian.
  6. Other colors, such as grey, orange, even purple, are usually associated with medications. Certain medications, such as bismuth-containing compounds, can turn manure grey or black. Feeding certain plants or feed additives can also give manure orange or purple hues. Again, if a color change is associated with other abnormal signs, then it would be advisable to speak with your veterinarian.
• Odor. Horse manure, while often not having the most pleasant smell, can usually be defined as earthy and not obnoxious, unlike carnivore (i.e., dog) manure. However, if a horse’s manure was suddenly repugnant and considered foul, this could be indicative of digestive disturbances, such as hindgut bacteria imbalances or upset.
• Parasites. Horses will pass either parasites (i.e., worms) or parasitic eggs in their manure. Eggs will not be visible, but any visible worms are indicative of a parasitic infection. It is always recommended to have your horses checked for parasites often with a fecal egg float and then, the horse treated accordingly. If worms are seen in the horse’s manure, you should speak with your veterinarian. Additionally, it is not uncommon to see worms in a horse’s manure after they have been treated with a dewormer (anthelmintic) and would be considered normal.
• Foreign objects. Any items seen like twine or sharp objects like wire could be potentially very dangerous for a horse and their digestive health. If seen, it would be advisable to check your horse’s stall, paddock, pastures for any objects that should be removed. If excessive sand or soil is in the manure, this also could pose a health risk like sand colic, and would require adjustments in how the horse is fed (i.e., feed up off ground).
• Quantity. Most horses will pass manure between 8 to 12 times per day. How much will depend on a variety of factors. For example, horses that eat high fiber diets will pass more manure each day than diets lower in fiber. Horses that exercise more often will pass more manure, as exercise is associated with greater gut motility. Younger or smaller horses will pass smaller piles of manure compared to older and bigger horses. On average, an adult full-sized horse can pass between 35 to 50 pounds of manure every day. That can be more than 9 tons of manure per year per horse!

As you can see, taking all the above factors into consideration of your horse’s manure can give you a good indication of their overall health and digestive well-being.

What Should I Do When My Horse’s Manure Changes?

As mentioned above, with any sudden changes to a horse’ manure, it can be an indication of an underlying health issue. We recommend that you:

• Observe and document. Note any changes to the color, consistency, odor, parasites or presence of any foreign objects. Also note any changes to your horse’s behavior or eating patterns.
• Review your horse’s diet and feeding practices. A change in a horse’s manure can be related to dietary imbalances or any sudden changes in the feed or horse’s feeding behavior. It would be advisable to consult with a qualified equine nutritionist to evaluate your feeding plan and any suggested changes.
• Maintain hydration. Always ensure your horse has access to clean and fresh water. If a change is associated with dehydration, take immediate steps to encourage water intake and consult your veterinarian. You may also want to check your water quality.
• Consider recent changes to your horse’s management. Did anything else change for your horse, like their environment or how they are managed? Sudden changes can impact the horse’s digestive system and would be important information to your veterinarian.
• Consult your veterinarian. With your notes, you can share the information with your veterinarian, and they can consult you on how to approach the situation.
• Regular monitoring. Closely monitor your horse’s feces and look for any further changes or if any abnormalities subside.

Take Home Message

Overall, evaluating your horse’s manure can tell you more than you probably thought. It is highly advisable to check your horse’s manure daily, as sudden changes can help alleviate any further health complications and costs of veterinary care. It is also highly recommended to check your horse’s manure after any changes in diet or management. If you have any questions, you can reach out to our equine specialists for any additional information.

Article By: Chris Mortensen, Ph.D.