Right... I know there are other threads I've already explained on, but the only one I can find now is the 'nerving' thread, which doesn't go into any detail because that's not what OP was asking...
Firstly, I'm curious that your horse was diagnosed with it because he was bucking. That's not a usual 'symptom' and I would have thought that if a horse has sore forefeet, he'd be *less* likely to buck.
'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 I think is more accurate, as bony changes are a *progression* of the 'syndrome'. The soft tissue strain/damage happens first, but cannot be seen on rads. It can however be evident in ultrasound or MRI. Curious
whether your horse had/has bony changes? If so, be interested to see the rads, as well as hoof pics.
ALL horses are born with weak, fatty DC's that aren't strong enough to support/be shock absorbers for the adult horse in high impact situations. According to Bowker & Ovnicek's research on mustangs, in ideal situation/lifestyle
, they only *begin*
to develop tough, fibrocartilaginous DC's and thick LC's with lots of tiny, shock absorbing blood vessels by the time they're around 4yo. This is one big reason why I believe we should not put conventional shoes on, or ask for hard/high impact work of immature horses.
Unfortunately, even when not shod/in high impact work, domestic horses very often do not develop strong caudal feet, due to 'cushy' paddock management & lifestyle. When they're asked to do something 'hard', their feet - and then the ligs, joints, tendons are put under too much strain. Physiologically correct hoof balance is also commonly a problem, and be it long toes, high heels, crushed flat heels... etc, these 'imbalances' can cause strain around the navicular region too. Adding conventional steel rims can cause them to feel less, but exacerbate damage, especially if on hard surfaces.
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 measures if the horse is 'past the point' of anything else working, but IME with a 9yo horse, there is a great chance that he's not 'too far gone'.
The only way I know of to successfully rehabilitate 'navicular syndrome' 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.
Anyway, that's my take. Hope it helps
And if you do give us pics, rads, more info etc, I will probably be able to elaborate on specifics relevant to your horse.
Comments on other's replies...
changing the hoof angle to improve the blood supply to the bone
Yeah, 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...
get my shoes down more frequently (4-6 weeks)
Yeah, whether you're doing shoes or not, trimming frequently enough to *keep*
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'.