I came across this post on my new favorite blog, Good Horsekeeping and thought I would share it. The focus is on the two extremes – from very unheatlhy to very healthy, but there is a lot of room in between the two. It is important to learn to recognize what hoof rings are telling you. It usually means there is some form of inflammation going on inside the hoof.
An upset in the horse’s metabolic system eventually shows itself in the hoof wall texture and horizontal rings. The hoof becomes a mirror of the internal imbalances.
MMP enzyme, (matrix metalloproteinase) controls the growth and direction of the laminae in the hooves. This enzyme is well regulated in a healthy system providing flexibility in the connective tissues of the hoof wall.
The cecum, in the hind gut is part of the digestive process. It is a fermentation sac containing microbials that assist in breaking down the forage.When the diet is high in grains and sugars this causes the bacterial population of the hind gut to rapidly increase damaging the lining of the colon and releasing toxins into the bloodstream.
4 yo Shetland Pony Mare
The pony had not been trimmed much until the time she foundered, and grazed on lush grass while under the care of the previous owner, resulting in a combination of probable metabolic and mechanical founder. Her X-rays and laminar wedge closeups appear in the posts below.
A tight regimen of frequent trimming as well as limited access to grass (using a muzzle) has been implemented, resulting in improved hoof form and a healthier body weight. The trimming focused on lowering the heels and backing up the toes, realigning the coffin bone parallel to the toe wall, as well as bringing it closer to a ground parallel orientation. The parallel hoof wall/coffin bone is a primary factor in the prevention of founder.
Somewhat difficult to see in the grass, but this is where the corrective trimming started, with high heels and very long toes. The red arrows at the toe show imminent coffin bone protrusion, along with a wide gulf separation between its edge and the wall. The bar, (red arrow), level with the frog, is high.
1 mo. 3 mos. 6 mos.
As the hoof wall grows down, the separation (all the way around the edge of the hoof) diminishes, and the white line becomes healthy and tight, enabling it to suspend the coffin bone in the hoof capsule.
1 mo. 6 mos.
By 6 months most of the hoof wall has grown down with less prominent rings. The remaining separation at the toe (red arrows) corresponds to the separation on the sole at the same time frame and will grow out in another month or so.
Founder & Laminitis (Under Construction)
The following diagram comes from the May ’99 issue of Practical Horseman:
This is a good depiction showing the progression from a healthy foot to a rotated one. However, the heels which give us most of the information about the possibility of rotation, have been obscured.
The important information with respect to rotation, laminitis, and founder can be found in the thickness of the sensitive laminae, as well as the orientation of the coffin bone relative to them.
1. Healthy Foot. The sensitive laminae (pink) are close, tight, and parallel to the insensitive laminae (white line). The actual foot resembles the shape of the healthy, diagrammed one. With its low heel, the coffin bone is parallel to the toe wall which is the surest way to ensure a healthy white line and healthy, tight, laminae that can solidly suspend the coffin bone and prevent founder espisode.
2. Mildly Pathological Foot. The wall of the coffin bone is no longer parallel to the hoof wall which causes the laminae to stretch at the bottom and begin to adopt a ‘wedge-shape’: narrower at the top at wider at the bottom. This puts constant stress on the overstretched laminae towards the bottom.
3. Severe Pathology. Founder – Rotation with Separation. The ‘wedge’ is extreme now, with the laminae much longer at the bottom than the top. The bone is far out of parallel with the hoof wall. The constant downward stress and pull on the lower part of the laminae has caused them to fail, allowing the suspension of the bone to the inside of the hoof wall to be lost and the bone to rotate.
Restricting a horse’s diet has many negative effects, as described in the following article from KAM Animal Services. Could the diet adopted out of necessity (if not outright desperation) by owners of insulin resistant horses and easy keepers, actually be contributing to their predisposition to laminitis?
”Insulin Resistance” is a trendy diagnosis made by lay people with regards to their own horses, based on information they glean from the internet. It is suspected as a cause in laminitis and founder, and horses are removed from most or all pasture, depriving them of their natural grazing needs in an attempt to remove sugars from the diet. I believe it is possible that this actually can cause the horse to experience even more stress and thus puts in motion a vicious cycle.Below are some excerpts from an article in The Horse, in which Tia Nelson DVM, discusses her experience in reducing signs of insulin resistance (such as cresty necks) in some horses, simply by improving their hoof form.
As she says, it is important to manage horses’ diets, especially easy keepers, but it can be very helpful to eliminate poor hoof form as a contributing factor. There is more on Insulin Resistance in a study posted on this blog, linked on this page here
Read the whole article here