Hoof Development in Foals
The existence of the equine species is dependent on the ability to flee danger from the moment of birth. This applies to both the new born foal as well as the dam, whom may be limited in her ability to move quickly during the post-partum period. Predators are attracted to the placenta and therefore it is vital for the mare and foal to move some distance away, even before the foal rests and nurses. Besides escaping predators, this early trek provides added benefits to the foal. These include the development of mental awareness, muscle coordination, proprioception, spinal alignment, and important early changes in the hooves.
The foal will try to rise, stumble, travel some distance and repeatedly fall in his attempts to follow the mare. This activity appears to be important for stretching muscles, straightening limbs, and developing coordination.
The hooves undergo some very important changes during this first travel across sometimes rocky and abrasive ground. Foals are born with a soft extension on the bottom of the hoof, which covers the end of the hoof wall as well as the frog. This probably serves to protect the mare from internal injury during foaling. The entire hoof wall is still fairly soft and is not designed to bear the foal’s entire weight. The frog comprises a large portion of the ground surface of the newborn hoof. The presence of the digital cushion at this stage of life is minimal, so the frog must perform the task of supporting the bone column.
Dr. Robert Bowker has noted that the front and hind coffin bones of newborn foals are identical in shape. It is only after the foal bears weight and fulcrums over the front limbs during movement that the front coffin bones begin to transform to a more rounded shape. This difference between front and hind shapes can be observed by two weeks in age. Therefore it appears that usage and activity are important factors in developing optimal coffin bone size and shape.
As the foal travels in his first hours of life the soft hoof wall rapidly wears off to meet the level of the sole. This places the frog on the ground which enables the frog to toughen. It is important to note that typically the frog responds to the hoof’s needs at birth, as it also will later in life. Examples of the need for the frog to adapt to specific circumstances are in cases of laminitis, or in hooves with weak cartilage structures and consequent negative plane coffin bone angles. The frog proliferates in order to supply additional support to the bone column in those circumstances. As well, in cases of catastrophic events where the hoof wall and sole are sloughed off, the frog is the first structure to regenerate and support the bone column.
Observations on foal’s hooves in a natural state are in stark comparison to what is seen in hooves of many domestic foals. Many breeders, in their attempt to provide the most secure environment for foaling, keep the mares and foals in deeply bedded stalls. Foals born during inclement weather or early in the year are sometimes confined to a small pen or stall several days or weeks after birth. These foals may miss that window of opportunity for optimal structural and hoof development. The hooves of foals confined to bedding or soft terrain, and subject to inactivity have been observed to undergo some potentially detrimental changes. First, the soft protective layer on the bottom of the hoof is not worn off, nor is the hoof wall allowed to shorten to the level of the sole. The frog is therefore not placed in contact with the ground and cannot adapt and support the bone column, and becomes atrophied. The entire outer hoof wall quickly dehydrates, shrinks and constricts the soft coffin bone.
Given the observations about coffin bone development in the early weeks of life, it is apparent that support from below via the frog, is of paramount importance in developing eventual size and shape of the hoof. Therefore, husbandry issues surrounding foal management at the time of birth may provide answers offering some help in resolving limb deformities, foot size relative to body size, and possibly even club foot syndrome.
This information offers us some sensible guidelines for foal husbandry when the natural elements are not available: First, BEGIN AT BIRTH! Allow foals out onto firm terrain with lots of exercise early in life, even before they nurse if possible. Hoof maintenance usually takes care of itself if the foal has access to optimal turn out on abrasive ground. In cases where hoof wall growth exceeds wear, regular trimming is required to maintain the hoof wall to the level of the sole all around the hoof. Where space is limited, more frequent trimming may be needed to insure that the hoof wall remains at sole level. Insure that the frog and sole are left in tact when trimming the wall. The frog normally takes care of itself as it is in contact with the ground, and will maintain functioning form as it was designed.
Keep in mind that if the hoof is not constantly in use, it will develop to a sub-standard state. In other words: “Use It or Lose It!”