I want to write about White Line Disease (also called seedy toe) today because I finally feel like I have a broad enough sample size of affected horses to analyze. There are certain conditions and qualities that I’ve noticed make a horse more prone to White Line Disease than others.
I’ll be listing them here with the goal of helping others trying to troubleshoot this meddlesome disease. And it really is meddlesome. It works quietly and, if gone unnoticed, can eat away most of the white line of a hoof in a year or two.
So let’s not let that happen!
My words today are based on what I’ve experienced as a barn manager and now owner of my own farm, in concert with the dozens of horses I’ve had the pleasure of trimming and training over the years. In short, I’ve found that White Line Disease is usually caused by an inadequate diet, obesity and lack of exercise.
Here are the types of horses I’ve found prone to White Line Disease. The first point is the most important connecting factor:
Inadequate Mineral Balance & Sugary Diet
An imbalanced diet runs common through the horses I’ve observed with White Line Disease (WLD).
These horses were left to pasture as the bulk of their diet. The problem with this method of management is that pasture doesn’t often contain every mineral and nutrient needed to both grow a healthy hoof and maintain the metabolic health of a horse.
Short, lush pasture grass also contains high levels of Non-Structural Carbohydrates (NCS). NCS are the starches and sugars found within the forage that horses eat. These starches and sugars negatively impact equine metabolic health as they can cause spikes in insulin and result in laminitis — the tearing, stretching and weakening of the lamina of the hoof.
This weak hoof with stretched lamina allows for the fungus that causes WLD to creep in and establish.
So, between the lack of nutrients often found in pasture grass and the addition of too many NCS, the hoof cannot grow out healthy tissue and becomes prone to White Line Disease.
The bottom line:
- Test pasture grasses and supply what trace minerals and nutrients are missing
- Limit turnout on grasses containing high levels of NSCs
Body Score of 6 and Over
This next point ties in with the inadequate diet discussed above because it’s often caused by improper nutrition, too.
Horses I’ve met, with a body score of 6 and over (I’m working with this chart), have been more prone to the fungus than horses at a moderate score or below.
Heavier weight means more pressure on the hooves which allows for easier stretching and cracking at the toe. The fungus behind White Line Disease loves dark, damp places so a new and unnoticed toe crack is the perfect place for it to work its way into.
Not only does the physical weight of the body put strain on hooves but often times, fleshier horses are associated with metabolic conditions that also distort the hooves in a way that causes cracking (see laminitis above).
The bottom line:
- Keep horses of moderate weight
Inactive Horses With No Exposure to Varied Terrain
The third thing that the affected horses have in common is that they were not regularly exercised or allowed to move at liberty.
This often ties in with both points mentioned above as weight gain can be associated with overfed and underworked horses, as well as horses left on pasture with high levels of NSCs.
Beyond weight gain spurred by inactivity and overfeeding, healthy hooves need lots of movement. They are dynamic in nature and respond to the varied terrains they clop over. Soft terrain builds average, bordering on weak, hooves. Challenging terrain promotes hoof growth that can handle the rigors of it i.e. strong hoof material.
Hoof growth is also aided by movement as movement promotes good blood flow to the hoof tissues that need it.
Unhealthy hooves with poor circulation and growth are prone to disease, including WLD.
The bottom line:
- Horses need to move — get them on a weekly exercise routine or provide turnout that prompts them to spend a good portion of their day traveling over varied terrain.
To Wrap Up
The types of horses I come across struggling with white line disease are the type you’d see out in the field, grazing and with full bellies. They weren’t worked often, if at all, and weren’t given supplemental nutrition.
They might get exercised once or twice a month and have their hooves picked out the same amount.
These horses were not part of a lesson program or show program but instead a part of breeding programs, sales barns or just privately kept by owners at their own homes.
If you’re struggling with White Line Disease and can see parts of your horse in my breakdown, then I suggest tackling the diet first. The rest really does fall into place from there. So, diet first and then make sure the horse gets plenty of movement and exercise so that they can maintain a moderate body score.
I hope this breakdown helped identify what might be letting that seedy toe take hold.
I’ll be writing future posts about how I balance the diet and movement of my own horses in a way that allows them to graze half the year and live White Line Disease free.