According to research done by Dr. Brian Hampson for his PhD thesis, "The practice of using the 'natural' foot model as the optimal morphometric model on which to base foot trimming practices may need to be reconsidered carefully."
In undertaking his PhD thesis, Dr. Hampson worked as a member of the Australian Brumby Research Unit [ABRU] within the School of Veterinary Science at the University of Queensland. The ABRU is attached to the Australian Equine Laminitis Research Unit which is headed by world renowned equine foot researcher, Professor Chris Pollitt BVSc PhD.
The ABRU was established with the aim of investigating the feral horses of Australia and applying the findings to improve foot health of the domestic horse.
Dr. Hampson questioned use of the feral horse foot as a benchmark model for foot health in domestic horses and saw the adoption of the model by some groups as possibly creating a tendency towards excessive removal of the bearing border of the distal hoof wall and sculpturing the foot in the shape of the popular hoof model.
Dr. Hampson's objectives included investigating the effect of varying environments (from alpine mountain to sandy desert) on foot morphology, foot health and related parameters on Australian and New Zealand feral horses, and also investigating important aspects of feral horse ecology that relate to foot morphology and function to improve the understanding of the interaction between ecology and foot variables.
This study found a profound effect of environment on feral horse feet. The gross morphology of feet was affected by a combination of substrate (footing) and the distance that horses travelled. Travel distance was determined by the separation between water and food sources in the habitat. Each environment studied produced a unique foot type in terms of general appearance, foot morphology and foot health.
Based on his research, Dr. Hampson determined that: given the moderate evidence of sub-optimal foot health, it may be inappropriate to judge the feral horse foot as a benchmark model for equine foot health.
Previous observers and proponents of the "natural" foot model were apparently unaware of this inner pathology but regardless, had made assumptions and recommendations for domestic foot care, such as promotion of solar loading and excessive bevelling of the distal hoof wall.
The study identifies the negative long term implications of substrate and movement on foot health. Care needs to be taken in choosing one environment over another because of possible harmful consequences.
Although feral horses living and travelling on hard substrate appear to have robust feet, modified by the environment and able to withstand locomotion over hard substrates, the current study suggests that there are some negative consequences associated with this lifestyle.
However, it is possible that the hard substrate foot type, because of its robust nature and biomechanical function, allows the feral horse to withstand significant foot pathology without showing overt lameness, thus assisting the horse to survive in extreme environments.
In light of this observation, further research is required to fully understand the impact of various models of hoof care and footings on the health and well being of domestic horses in managed care.