A number of factors can result in diarrhea in horses. Take a look at the most common causes, and some tips on how to deal with them.

I’ve only had to deal with diarrhea in my horses once in the last 20 years. It was after Cody, my Thoroughbred, broke into the orchard and feasted on apples all through the night. Knowing the cause of the diarrhea was a big help, and with the support of some herbs, it cleared up in a few days.

In my clinic, I see equine diarrhea on a more regular basis. It typically occurs when a feed change happens too quickly, or when the spring grass is coming in. This type of diarrhea normally passes in a few days with the correct management. But sometimes, equine diarrhea isn’t as simple as that, and getting to the bottom of it can be hard work. A horse’s manure should consist of well-formed balls with no runniness or watery discharge. The microbial balance in the gut helps keep the pH in the correct range, and when there’s an issue with this balance, the manure changes. In short, diarrhea is a symptom of an issue in the gut.

Causes and treatment of diarrhea

Let’s look at some of the causes of diarrhea and determine some effective courses of action. Keep in mind that if diarrhea lasts more than two weeks, it’s classed as chronic and your vet should be contacted.

1. Feed change

All new feed should be introduced slowly. Horses going out on new grass should be turned out for short periods daily (one hour to begin with), gradually building up to full turnout. When not on grass, keep horses on hay. To help their digestion cope better you can add sprouted seeds for enzyme efficacy, which in turn helps breakdown proteins, carbohydrates and lipids and adds in vast amounts of antioxidants.

Live yeast can help as well, as can herbs in dried or liquid form (herbal tea or tincture). Dried herbs can be simply added to feed, while herbal teas can be used to dampen down feed. I recommend fennel seed, peppermint, chamomile, meadowsweet, lemon balm, red raspberry leaf and nettles. Sometimes just adding one of these herbs will help.

2. Nervousness

Some horses struggle with stress from things like traveling or lack of equine company. This can often result in stress-related diarrhea. For horses that might need some support when on the road or leaving friends, herbs like lemon balm, hops, oats and skullcap can really help. Some horses who worry or are anxious can stay on an herbal remedy for a few weeks. Use herbs such as passion flower, lemon balm, lime flowers, oat seed and vervain that nourish the nervous system and restore balance. Also, remember that horses need regular turnout and friends to thrive.

3. Ingested toxins

A number of substances are toxic to horses – yew, oleander, rat poison, plants that have been sprayed with herbicides, rotting hay, red maple and ragwort, to name a few. Depending on your horse’s age, as well as what and how much he’s ingested, you may need to call a vet. When in doubt, call. Using activated charcoal or bentonite clay can help bind toxins, while milk thistle seed powder can support the liver.

4. Antibiotics

Some antibiotics can induce diarrhea. Probiotics can be variable in how well they work, so keep in mind the CFU (colony forming units of good bacteria) when buying one. The higher the better. Brewer’s yeast can also be helpful.

5. Parasites

Weight loss accompanied by diarrhea can be a sign of parasites. Keeping good records of your deworming program, proper pasture management, and taking fecal counts when needed will contribute to good parasite control.

6. Food sensitivity

The horse’s digestive system is sensitive to change, so all new foods need to be introduced slowly. If you suspect a food allergy, remove feed immediately. Herbs and food to help with sensitivity include soaked hemp seed, whole soaked oats, chia seeds, live enzymes from sprouted seeds, slippery elm, marshmallow root and chamomile.

7. Ingesting sand

Some geographical areas are known for sand issues. If you live in one of these areas, you can help your horse by feeding a commercial sand remover, or psyllium husks, on and off. You may need to need to look at your horse’s environment and make changes accordingly. For instance, try adding in extra hay nets or using rubber mats at feed stations. Slow feeders can also be helpful in these situations.

8. Age

Older horses can get bouts of diarrhea due to poorly-functioning digestive systems. Sprouted seeds can help seniors digest better. If the horse has dental issues, sprouted seeds can be mashed up or blended into a smoothie to help with absorption. One of my favorite “old timer” smoothies is a combination of cold chamomile tea, sprouted seeds, meadowsweet powder, ginger powder and slippery elm powder. Add to a blender and feed to your older horse to help heal his gut and improve digestion.

9. Digestive infection

Herbs to help with digestive infection include garlic, thyme, Echinacea, cinnamon, calendula and goldenseal. If you suspect infection, speak with your vet before using herbs.

Diarrhea doesn’t just happen for no reason. As caretakers for our horses, we need to do what we can to help them adjust to the environments we create for them!