Horses were not born with iron shoes on. Wild horses don't wear shoes they run bare footed. So what is it humans are doing wrong. (?)
Lot's of things. In example....
1. Presuming that because a horse is not born with orthotics that none will be needed for the domesticated horse expected to meet the use based expectations of their owner.
2. Presuming that there is significant, comparative relationship between the needs of the feral/wild horse and that of the discipline bred, domesticated horse expected to meet the performance needs of the owner.
3. Presuming that wild horses, grazing at liberty over thousands of acres of semi-arid land, have the same distal limb management needs as the domesticated animal managed in a completely different environment and expected to meet use based expectations of a human owner.
4. Failing to recognize and acknowledge that the routine mechanical/pathological failures that are often managed or corrected in the longer lived domestic horse are a routine death sentence for the wild horse.
5. Engaging in internet counsel to owners of lame horses even though you possess no formal training or significant experience in the trades of either the professional farrier or veterinarian. Hypothetical case in point... if this particular owners horse were to die because she followed your counsel as to how best to manage her horses problems, are you willing to take personal and professional responsibility for that outcome? Should her horse suddenly suffer mechanical founder due trauma the vascular bed, a potential consequence of inadequate solar depth and possible distal descent, are you prepared to counsel said owner through the management and treatment of such pathology?
I generally leave my horse bare footed for as long as I can and only use shoes when I am riding on stone, or paved roads. Natural is the way in my humble opinion. With exceptions as mentioned.
If "natural is the way" then why are their exceptions? How does your "management" and experience of a single horse living and used in New Zealand qualify you to provide lameness counsel to an owner whose horse lives near the Adriatic sea? Is it possible that environment and intended use may be considerably different than your own?
Pain for the horse I do not advicate, but if it is short lived and improves the horses hooves then keep an eye on it and continue. The horse will benifit in the long run.
Really? What exactly is the owner supposed to "keep an eye on". When did pain become a curative property of healthy transition? How exactly does pain become beneficial in the long run and is there any point at which you might suggest that perhaps the pain is symptomatic of a problem which may or may not require professional attention?
Running bare foot after a while the hoof will increase in size and spread a little. That makes the hoof able to spread the load over a wider surface resulting in less preasure points.
Really? So if I leave a club-footed horse barefoot, that foot will increase in size and spread, reducing pressure points? How about a horse suffering hi-lo syndrome? Bilateral limb length disparity? What if that "spreading" is a consequence of capsule distortion at the quarters and subsequent quarter cracks? Barefoot cures all ills?
Got to be better in the long run.
How is leaving a flat-footed, thin soled horse suffering in discomfort over challenging terrain better in the long run? Make 'em hurt until they don't so you won't have to incur the expense and personal responsibility that comes with the ownership of a domestic horse? Why should a farrier or vet help you subsidize the neglectful, unnecessary discomfort of a domestic horse?
My horse Savannah had huge feet like big dinner plates I often commented she could walk on water. No problems with her hooves.
And that singular, completely different, anecdotal example somehow qualifies you to advise this particular horse owner how???
Stella has the shoes off as often as I can in an attempt to improve the size of her hooves. Not a great help for you but encouragement if bare foot is the aim.
Let's cut to the chase. Why is barefoot the "aim"? Why isn't the "aim" the relief/correction of a horse in discomfort? Why isn't the "aim" the professional administration of whatever methodology best meets the needs of the horse and the intended environmental/performance use of that animal by the owner?
Also if you live in a dry area make a foot bath and stand the horse in water daily, the hooves benifit from moisture.
Let's just simplify this mess. You have absolutely no formal experience or training whatsoever in the proper management of the equine distal limb, domestic or wild, regardless of environment or use, but somehow feel utterly and completely comfortable dispensing irresponsible and nonsensical commentary and opinion to an owner with a horse in some level of undiagnosed discomfort. And, of course, should this particular horse happen to suffer through and survive the trauma of their "barefoot transition experience", you'll be the first to claim "see, I told you so!", right?
I've got to ask. Do you also and routinely play doctor on website forums devoted to human patients seeking help?
To the OP... your horse has little foot mass/volume, is flat and probably thin soled as evidenced by the shallow depth of the collateral commmissures near the apex of the frog and bearing as much or more load on the anterior solar tissues as the distal capsule wall. Radiographs would likely indicate no more and probably less than 10mm of sole thickness under the solar margin of the distal phalanx. This lack of depth is causal in excess pressure on the vascular bed and the tenderness your horse experiences when traversing difficult or challenging terrain. That pressure creates inflammation of the soft solar tissues and is likely causal in the edema visible in the distal limb (distal to and including the proximal phalangeal joint).
Over time the exposed solar tissues may harden enough to afford the foot some protection/relief, as will any wall growth that reduces pressure on those tissues. This is the "transition" period you may hear others describe. It's a painful, unnecessary transition. Risks include trauma related sub-solar bruising, possible abscess (secondary infection associated with bruising/trauma) and, worst case scenario's of mechanically induced laminitis.
The application of orthotics can reduce that risk by relieving solar pressure and providing needed protection until such time as the animal grows enough wall length to afford solar relief of sensitive tissues. Once that is accomplished (presuming ever), the orthotics can be removed, the foot more conservatively trimmed to balance and the horse allowed to demonstrate what barefoot capability can be achieved. That "transition" would be comparatively low risk, low cost and should require no more than 6-8 weeks to achieve.
Radiographs would remove speculation about solar depth and coffin bone position within the hoof capsule, providing a better diagnostic and evaluation of your horses ability to meet your performance expectations.
Barefoot should not be a "try it and see" effort. It is a management protocol decision that should be based on the needs of the horse and your use based expectations of the animal.
The comment that "She is fine now, she is walking very careful over the road, but not lame" is an oxymoron. The horse is either sound or it is not. Horses absent lameness do not "walk very careful over the road". Your farrier and vet are best qualified to assist you in determining the optimal protocol to meet your horses needs.