Why does my horse eat mud and other unusual things?

Three horses, a gray, a bay, and a chestnut grazing in a pasture with a split-rail fence and trees in the background on a sunny day.
sponsored post

Here we welcome equine feed manufacturer, Dodson & Horrell, to help answer a question often asked by horse owners; why does my horse eat mud?

Guest Post: Dodson & Horrell

When horses eat Soil (geophagia), chew fencing, or generally lick unusual things, owners tend to worry. Historically, if a horse were seen chewing a fence (non-crib biting) or actively eating soil, it would have been considered that the horse is deficient in essential minerals in their diet.

Unfortunately, research has shown there is no strong evidence for this, however, if your horse has started this behaviour, it is still a good idea to first review your feeding programme.

Please seek nutritional advice to check if your horse is reaching the minimum requirements of vitamins and minerals they need each day. We have a friendly team of nutritionists available online through the website website at Dodson & Horrell or call their helpline on 01270 782223.

Why does horse eat mud. One horse grazing in the meadow. One beautiful bay horse.
Why does my horse eat mud?

Foals actively eat soil and their mother’s droppings (coprophagy), as their gut microbiome is developing. This helps to populate their gut with the best microbes to aid its protection from local infectious agents and give it the best population of microbes to efficiently digest the forage and feed that they, and their mother, are currently consuming.

We can encourage a healthy gut microflora in any horse, pony, or foal, by using a product such as Dodson & Horrell Digestive Support supplement. It contains a blend of Prebiotics, Probiotic, Psyllium, and herbs. The active ingredients in this supplement help ‘good bacteria’ grow and restrict ‘bad’ bacteria growth to support digestive tract functionality.

Dodson & Horrell Digestive Support

Some horses will lick cement and walls if they are deficient in salt. Placing a salt lick in their stable, or better yet, adding balanced electrolytes to their diet, can help satisfy their needs.

An older horse who has recently started this behaviour should potentially also be checked by their vet. This is because horses with PPID (Pars Pituitary Intermedia Dysfunction), commonly known as Cushings Disease, can cause hormonal imbalances that result in excessive sweating. The skin and coat can begin to appear dusty and/or white due to the build-up of salt from the sweat.

Dodson & Horrell Electrolytes

The loss of essential salts in sweat may exceed that which they consume per day through their normal diet and drinking. This can encourage the individual to seek alternative sources of these salts (i.e. walls and soil). In a Cushings horse showing this behaviour, provision of electrolytes daily may help.

As an example, a 200kg pony with Cushings would require a maintenance dose of Dodson & Horrell Electrolytes of 24g per day (usually equating to a 1/2 scoop provided inside each tub). At this dose rate, a 2kg tub would last approximately 3 months, providing a very cost-effective way to nutritionally support the veterinary treatment that will be required to control this disease.

Licking of surfaces in some horses is a ‘stereotypic behaviour’, which has sometimes been linked to increased social and individual stress levels. Repetition of these repetitive behaviours (like licking) releases dopamine in the horse, resulting in a self-soothing response.

We can anthropomorphise this into the same self-soothing behaviour elicited from someone who sucks their thumb. Unfortunately, once these behaviours are in place, some horses will not revert back to ‘normal’ even if the root cause has been fixed.

In hotter climates, research has shown that horses who eat sand have a significantly higher chance of having severe gastric ulcers (stomach ulcers). It has been theorised that they perform this behaviour to try to help fill their stomachs and ease the pain of the ulcers, similar to the dopamine response associated with stereotypical behaviours above. It is still unclear, however, if the sand eating or the stomach ulcers come first in this course of events.

Overall, if your horse is consuming dirt, or has started an unusual behaviour, their management programme including their feeding should be reviewed, and veterinary advice should be sought to assess their overall health and intestinal health including their worm status.

If your horse is consistently eating dirt and soil please also consider increasing the amount of Psyllium present in the diet, to help prevent the accumulation of sand content that can accumulate in the gut and lead to an increased risk of sand-impaction colic.