Navicular Disease / Caudal Hoof Pain Overview
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'Navicular Syndrome' has been used to describe unexplained caudal(back of) hoof pain, whereas 'Navicular Disease' was the diagnosis when rads showed bony changes to the navicular bone. These days, it seems that vets tend to call it all 'Syndrome'. Which is more accurate, as bony changes are a *progression* of the 'syndrome' & it's not really a 'disease'. It is also known these days as 'Caudal Heel Pain Syndrome'. The soft tissue strain/damage happens first, but cannot be seen on rads. It can however be evident in ultrasound or MRI.
Signs include intermittent or chronic lameness, especially on a tight circle; shortened stride; tripping and pain upon pressure with hoof testers to the area. Physiologically incorrect hoof form/trimming is very commonly a cause, although no single 'conformation' of hoof is associated. It can be long toes, 'boxy feet' with high heels, crushed flat heels, 'broken forward/back' hoof-pastern angles... etc. These 'imbalances' can cause strain around the navicular region as well as elsewhere. This can be rather vague, and any of these signs can be associated with other problems, and absence of radiographic 'proof' of damage to the bone has led to it's 'mystery' reputation.
Conventionally, 'navicular' has been thought of as a mystery, incurable & progressive. Therefore conventional 'treatments' are only palliative - they address the symptoms as best they can. Unfortunately, many of these measures - such as shoes with wedges etc - only further exacerbate the underlying problems, so cause the 'disease' to continue progressing. That's why 'treatment' tends to progress too, as regular shoes, then bar shoes, then wedges, higher wedges... etc progressively fail to work.
Thankfully though, it does tend to be a quite slow progression, and if the *causes*, that we now have pretty good understanding of, are also addressed, esp if it's caught early, then the 'disease' can generally be prevented from getting worse, if not actually healed or at least improved. **Bony changes won't change back to how they were, but this doesn't tend to matter in the scheme of things. So I'd highly recommend you look to theory/practice that aims to *heal* hooves. You can always go back to palliative only measures if the horse is 'past the point' of anything else working.
The only way I know of to *successfully rehabilitate* 'navicular syndrome'(as opposed to palliatively manage) is to keep shoes off. To keep hooves trimmed in a physiologically ideal manner with short 'breakover', low heels and aligned phalanges(P1, P2, P3). To protect and support hooves where necessary with hoof boots or alternatives like Eponas or Easyshoes, with or without padding. To use something for pain if absolutely necessary in the short term and give the horse a break from any work for a while, to allow the soft tissue damage a chance to heal. Then there's a good chance the horse will return to being sound enough for regular work.
It is, of course often not as easy as that sounds. It is not always possible, depending on extent of damage, to bring a horse all the way to soundness. High impact hard work may well be still beyond them, even in hoof boots, so trail riding or arena work may be as much as they can stand. Some horses may be past that much even. Very few, IME, unless very extensively damaged already, can't at least be brought to 'paddock soundness' without special shoes. If they can't be made paddock sound - they're too old, too much damage - THEN I recon it's time to consider conventional palliative shoeing & wedging.
Comments on comments...
Changing the hoof angle improves the blood supply to the bone
It's been found that changing the angle - eg wedging heels - is a commonly effective palliative. It doesn't improve blood supply tho. It is thought the relief is felt because of changing the point of most force on the foot, bringing it further forward. So the hoof is 'relieved' of pain at that point, until the new spot has been under strain for long enough to make that sore. Then they wedge a little higher...
Should I get my shoes done more frequently? (4-6 weeks say?)
Whether you're doing shoes or not, trimming frequently enough to [I]*keep*[/I] hooves in optimal form, rather than waiting for them to overgrow & distort between trims is important. Generally I find around 3-5 weekly is ideal.
You could consider ProStride, or PRP, or IRAP injections to help with the inflammation
Yes, there are options such as this that while palliative, aren't harmful, so can be used as part of successful rehab, not just as a palliative for horses 'past the point'.
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