Mycotoxins in Horses:
The Hidden Challenge in Feed and Forage

Mycotoxins in Horses: The Hidden Challenge in Feed and Forage

You can’t see them with the naked eye, yet they may still be present in your horse’s daily diet. Mycotoxins are naturally occurring compounds produced by certain moulds and can be found in forage, feed and bedding such as straw. Although often invisible, they may contribute to an increased nutritional challenge and can affect your horse’s overall wellbeing, performance and resilience. Because the signs are often non-specific, mycotoxins are not always considered as a possible contributing factor.

What are mycotoxins?

Mycotoxins are naturally occurring toxic compounds produced by certain species of mould. These moulds can grow on forage such as grass, hay, haylage and straw under suitable environmental conditions.

One of the challenges with mycotoxins is that they may remain present even after the visible mould has disappeared. They are also relatively stable and can withstand drying, heating and many feed processing methods.

A batch of forage may appear perfectly normal while still containing mycotoxins. Equally, visible mould does not necessarily indicate high levels of mycotoxins. This makes them difficult to identify as a potential contributing factor when horses experience vague or recurring health or performance issues.

Mycotoxins are also often unevenly distributed throughout a batch of forage or feed. This can result in so-called “hotspots”, where concentrations are considerably higher than elsewhere in the same batch.

For horses, moulds belonging to the Aspergillus and Fusarium genera are among the most relevant, as they are capable of producing several different mycotoxins that may affect feed quality and horse wellbeing.

How can mycotoxins affect your horse?

Horses naturally encounter small amounts of moulds and mycotoxins throughout their lives. Healthy horses can often cope with limited exposure. However, prolonged exposure, higher concentrations, or additional challenges such as stress, illness or reduced condition may increase the overall burden on the horse.

Mycotoxins may place additional pressure on several normal body functions, particularly digestive health, immune function and the body’s natural detoxification processes.

The signs are often subtle and can vary between individual horses. They may include:

• Reduced vitality
• Changes in droppings or digestive function
• Loss of condition
• Reduced energy levels or performance
• Changes in behaviour
• A dull coat or reduced overall wellbeing

Because these signs are general and may develop gradually, the possible role of mycotoxins is not always immediately recognised.

How can you reduce the risk?

Completely eliminating mycotoxins is rarely possible. However, good feed management can help minimise the risk.

Store feed correctly

• Keep feed in a clean, dry and well-ventilated area.
• Prevent damage to feed bags and packaging.
• Protect storage areas from rodents and other pests.
• Follow a First In, First Out (FIFO) stock rotation system.
• Discard any mouldy feed or forage completely.

Monitor forage quality

Regularly inspect hay, haylage and silage for unusual smells, colour changes or poor texture. While visual inspection cannot confirm whether mycotoxins are present, it remains an important part of assessing overall forage quality.

Consider forage analysis

If you have ongoing concerns about forage quality or unexplained changes in your horse’s condition, laboratory analysis may provide useful information. Because mycotoxins are often unevenly distributed, representative sampling from several locations within the forage batch is recommended.

Nutritional support during periods of increased challenge

During periods when forage quality is variable or horses may be exposed to higher levels of naturally occurring undesirable substances, nutritional support may help maintain normal digestive function.

HorseFlex Toxin Support is a complementary feed for horses, formulated to support normal digestive function and the body’s natural elimination processes. The formula contains bentonite, marine algae, oregano, thyme and curcumin, providing additional nutritional support during changes in forage quality.

Supporting your horse every day

Although mycotoxins cannot always be seen, good forage management and careful nutritional support can help maintain your horse’s digestive health and overall wellbeing. By paying close attention to forage quality and providing appropriate nutritional support when needed, you can help your horse maintain normal vitality and performance as part of a balanced diet and good management.