A horse's digestive system is long, complex and heavily reliant on the microbes living in its hindgut. When that system is under strain, the signs are often gradual and easy to put down to something else, such as the weather, a change of rider or simply age. This article sets out the changes worth noticing, what they can point to and what to do next. It is general information from Horse Probiotics, not veterinary advice, and it is no substitute for an examination by your vet.
Start with what is normal for your horse
Every horse has its own normal. Some always pass slightly softer droppings, some are naturally fussy eaters and some drink more than others. Redwings recommends checking all horses carefully at least twice a day, and those routine checks are the best way to learn what normal looks like. Note how many droppings your horse usually passes overnight, how quickly it finishes its feed and how much water it drinks from a bucket. When something changes, you will spot it sooner and be able to describe it accurately to your vet.
Signs that can point to a digestive problem
1. Changes in droppings
Redwings lists changes in droppings among the signs of colic, whether that means fewer droppings than usual, loose droppings or diarrhoea. Outside an emergency, droppings that are consistently looser than normal, or liquid passed before or after otherwise normal droppings, can suggest the hindgut is not fermenting fibre as steadily as it should. That second pattern is often called free faecal water, and our article on free faecal water in horses looks at it in detail. Fewer or drier droppings matter too, particularly in winter when horses may drink less.
2. Reduced appetite or picky eating
Leaving feed, picking through forage or going off a favourite meal can be a sign of discomfort somewhere in the digestive tract, from the mouth to the hindgut. It can also be a simple dislike of something new in the bucket. Track it over a few days, and remember that reduced appetite is also one of the signs Redwings associates with colic.
3. Gradual weight loss
A horse that drops condition while apparently eating well may not be getting full value from its feed. Weight loss has many possible causes, including dental problems, worms, gastric ulcers and illness. World Horse Welfare advises checking weight regularly with a weigh tape and fat scoring, and says that horses with a fat score below 2 on its 0 to 5 scale should be checked by a vet. In older horses, Redwings is clear that being underweight should never be accepted as normal.
4. A dull coat or low energy
A coat that loses its shine, or a horse that seems flat and lacking energy, can reflect overall nutrition and digestion. On its own it is a mild and non-specific sign, but alongside any of the other changes on this list it is worth recording.
5. Girthiness and changes in behaviour
Some horses with digestive discomfort react when the girth is tightened or when they are brushed around the flanks, or become resistant and irritable under saddle. Gastric ulcers are one possible cause, but saddle fit, back pain and lameness can produce the same picture. Gastric ulcers can only be confirmed by gastroscopy, and our gastric supplements guide explains why diagnosis matters before choosing any product.
6. Low-grade signs of discomfort
Redwings describes a range of subtler signs that can accompany colic, including tail swishing, fast or laboured breathing, tension in the face and body, and looking round at the flanks. A horse that shows these briefly and repeatedly, or seems tucked up through the belly, needs attention.
7. Recurrent mild colic
Repeated bouts of low-grade colic are always a reason for a full veterinary investigation. Our article on colic warning signs covers the early signs and what to do while you wait for the vet. Research behind the University of Nottingham's REACT colic campaign found that around 90% of horse owners struggle to spot early signs of colic, and that one in three emergency vet call-outs were due to colic.
What commonly causes digestive upset?
Most digestive problems have more than one contributing factor. The most common are worth reviewing whenever you notice a change.
- Sudden changes of diet or housing. A University of Nottingham systematic review in PLOS ONE found changes in feed and recent changes in housing had the strongest evidence among management-related colic risk factors.
- Large starchy meals and long gaps without forage. Both work against the way the equine gut is designed to work, and our page on hindgut health explains why.
- Teeth. Redwings lists weight loss, bad breath, dropping food and loose droppings among the signs of dental problems.
- Worms. Redwings recommends faecal worm egg counts every few months and warns that by the time signs of a worm problem appear, the case is usually advanced.
- Stress, travel and medication. Transport, fasting and some medicines, particularly antibiotics, are recognised influences on the gut microbiota.
What to do next
- Talk to your vet if signs are persistent, getting worse or you are unsure what you are seeing.
- Keep a diary of droppings, appetite, water intake, weight and behaviour, so that you and your vet can see real trends.
- Review the diet with the basics in mind: plenty of forage, small hard feeds and gradual changes. Our guide to how much forage a horse needs is a good starting point.
- Check teeth and worm control are up to date.
- Consider whether a supplement has a role once your vet has ruled out other causes. Our equine probiotics guide explains what these products can and cannot do, and the reviews hub assesses individual products from their published information.
A gut supplement is designed to support normal digestion. It does not treat ulcers, worms, dental disease or colic, and using one to cover up a persistent sign can delay a diagnosis that matters.