Horse owners have long observed some horses picking up hay, dipping it into their water bucket, and then eating it. While often dismissed as an odd stable habit, new research from Hartpury University suggests forage dunking may be far more common than previously thought and could even be linked to respiratory health.
The preliminary study, published in the International Journal of Equine Science, is the first to investigate the prevalence of forage dunking behaviour in UK horses and explore possible links with management practices, discipline and health conditions.
A surprisingly common behaviour
Researchers surveyed 414 horse owners across the UK and found that 42.7% of horses were reported to dunk their forage before eating it.
The behaviour was seen across all types of horses but was significantly more common in dressage horses, where over half (54.8%) were reported to dunk their forage. Horses kept in American barn-style stabling were also significantly more likely to display the behaviour than those housed in other stable designs.
More than simply wetting dry hay?
Forage dunking has traditionally been thought to help horses moisten dry forage, making it easier to chew or swallow, particularly in horses with dental problems.
However, the new findings suggest there may be more to the behaviour.
Although around half of owners reported that horses dunked more when fed dry hay, the behaviour often continued even when forage was soaked or steamed. This indicates that simply adding moisture to forage does not fully explain why horses continue to dunk it.
A possible link with respiratory disease
One of the most interesting findings was the apparent relationship between forage dunking and certain respiratory conditions.
Among horses reported to have health conditions, almost half displayed forage dunking behaviour. The strongest association was seen in horses with laryngeal hemiplegia (roaring), where more than 80% were reported to dunk their forage.
The researchers suggest this could indicate that dampened forage is easier or more comfortable for horses with upper airway disorders to eat, although they stress that further research is needed to understand exactly why.
This finding is particularly interesting given the growing recognition of the importance of respiratory health in equine welfare and performance.
What does this mean for owners?
The study does not suggest that forage dunking is harmful, nor does it recommend trying to stop the behaviour.
Instead, the researchers believe it should prompt owners to observe their horses more closely. While some horses may simply prefer damp forage, persistent forage dunking, particularly if accompanied by other signs such as noisy breathing, coughing, difficulty swallowing or weight loss, may justify a discussion with a veterinarian to rule out underlying dental or respiratory problems.
The authors also highlight that the behaviour deserves much more scientific investigation before firm conclusions can be drawn.
The bottom line
Many horse owners have regarded forage dunking as little more than a messy stable habit. This study suggests it may be considerably more complex.
Whether it reflects individual preference, helps horses manage airway or dental discomfort, or serves another purpose entirely remains unclear. What is clear is that forage dunking is common, occurring in more than four out of every ten horses surveyed, and deserves greater attention from researchers and horse owners alike.
Reference
Brown, H. & Lee, K. (2026). A Preliminary Investigation into Forage Dunking Behavior in Horses in the UK. International Journal of Equine Science. https://doi.org/10.64292/ijes.211
