[Text] Christine Pinna
If there is one thing that has been a complete game-changer for me in the last fifteen years of barefoot trimming, it would have to be learning to read the horse’s hoof wall in order to understand what has happened in the horse’s life in the last few months. This often shows me why we have a hoof issue or what hoof issues we can expect to encounter in the future. Armed with this knowledge, I have a good idea of whether we need to intervene urgently and how to do this, or if we can calm down and just wait things out.
When I talk about ‘reading the wall’, I am mainly focussing on event lines. These are the horizontal rings that one sees on almost every horse’s feet, at least from time to time. The more pronounced the line, the more severe and the harder the correlating even was on the horse’s body.
Have you ever wondered what causes these event lines? Many times we can work out precisely what the cause was, or at least the probable cause. Other times, we really won’t know. Generally, I would say that the more problematic event lines will have an obvious cause, and these are the ones we want to take note of in the hopes that we don’t have a repeat event or so that we can try to do damage control while the hoof grows out.
Causes
Event lines can be caused by the following:
- High sugar diet
- Metabolic disease/Insulin Resistance
- Diet change
- Season change
- Deworming
- Illness
- Reaction to medication or a vaccine
- Toxicity
- Excessively hard work on hard ground (concussion line)
- Shoes being pulled
- Abscess
- Mare foaling down
Sugar sensitivity
By far the most common cause of event lines would be sugar sensitivity. Why is this? The main cause is probably the romantic idea that most of us grew up where the horse can graze on lush green pastures for hours every day and then come in and eat a hearty meal of concentrates. Unfortunately, as many are now realising, this is not ideal for the horse. While a small amount of concentrates and a restricted amount of time on lush grazing might be fine for some horses, others can’t cope with either, even in small amounts, without heading into full-blown laminitis. Horses with sugar sensitivities usually have multiple event lines seen close to one another.
Dietary changes
I would say that the second most common causes of event lines are dietary changes. Hopefully, in the case of my clients, for the better. When we move horses onto lower-sugar concentrates or off commercially mixed concentrates entirely and onto properly formulated, hoof-friendly mineral supplements and foodstuffs, horses inevitably start to grow out a much tighter hoof wall. This can initially cause a change in the appearance of the event lines, but the event lines will disappear or reduce in number over the next couple of months. Similarly, a few months down the line, any flares present in the wall will have mostly grown out, and the horses will be left with much neater hooves that are less likely to flare or crack.
Dewormers, medication and vaccines
I have witnessed a fair number of horses reacting to dewormers, which disrupt things in the gut temporarily. For many horses, it is a minor disruption, which will go largely unnoticed, but for the odd few, this may trigger full-blown laminitis. Horses that get sick and are on medication are also quite likely to push out an event line. Generally, the sicker the horse and the stronger the medication, the more severe the stress line appears. These horses may even have a predisposition to abscessing and usually, an event line will be seen from the same time, becoming very obvious maybe a month or two after the incident.
Effect on the hoof wall
The frustrating side effect of an event line is the weakening of the outer hoof wall and white line (laminae). This happens rather dramatically in many cases. This weakened hoof wall may not be a problem in stable weather conditions such as a dry winter, but generally prolonged wet conditions or worse, alternating wet and dry spells can wreak havoc. The result can be anything from minor chipping and cracks to much deeper cracks and seedy toe. What you will see, however, is that most cracks and chips or seedy toe do not extend much past the event line, provided it can be linked to an isolated event. This is comforting as the hoof wall above the line will typically be much stronger than that below the event line, meaning that once the event line reaches the bottom of the hoof and grows out, the hoof should return to its previous strength without much intervention. If there are multiple event lines and ongoing hoof weakness, one would assess the diet quite seriously.
How to tackle event lines
In many cases knowing what to expect can have a calming effect on most frantic horse owners. For clients that remain frantic, I give them things to do. Whether it helps is a different story, but if it helps the owner, that is good enough for me. Generally, this is my plan of action when spotting event lines:
1) I try to figure out the cause of the event line by asking some questions about the horse’s history. Was he sick? When was he last dewormed? Has he had any recent diet changes? If the horse’s diet is quite good, there is probably a different cause. If this is a passing event such as the horse got sick or reacted to medication, we may discuss a game plan for if the horse was to get sick again. Some herbal and homeopathic remedies can either help to reduce the effects of more serious medication or may even be able to replace them without the risk of side effects. In this case, it is important that one uses a vet who actively works with and studies natural remedies, perhaps in conjunction with an experienced herbalist. Of course, if the diet is an ongoing problem, I will chat to the client extensively about hoof friendly nutrition and probably refer them to my nutritionist for further support.
2) I explain what might happen if dry and wet spells occur and how this may further weaken the old-growth, resulting in cracks, chips and possible seedy toe.
3) I point out the new, stronger and less flared growth and estimate more or less how much longer we will have to wait for the whole hoof capsule to heal. Obviously, if further events occur, things may go backwards along the way.
4) I then discuss topical options. If the owner wants to be proactive, I will suggest a topical remedy be applied daily. While I see great results with topical disinfectants for thrush and contracted heels, I am waiting to be blown away by something topical that will beat the effects of solid nutrition when it comes to weakened hoof walls. This is not to say that it isn’t possible, but just that I haven’t seen it yet. I have worked with many cases of bad seedy toe that only came right when the internal problems were addressed, but if a product comes along that does make a big change, I’d love to hear about it! In most cases, we only treated the hooves internally without topical disinfectants.
5) As my understanding is that not much can be done to fix the old and damaged hoof wall, I try not to focus on it too much apart from keeping it neat and regularly trimmed. I also do everything I can to encourage good quality, strong growth to come in to replace the old hoof wall, predominantly through dietary interventions.