Using the analogy of a toddling child learning to walk, who relies on the two hands of their parent to support them, and an older child who will take the hand of their parent but it provides no physical means of support to them (My personal addition being that they take the hand for comfort, security or love - sometimes a support that a horse needs during rehabilitation or transition), they explained this to be the difference between a flare and a deviation. But continued saying the difference doesn´t matter, because flare, though ugly, is weak and therefore benign, therefore wont affect the soundness of the horse.
Presuming elements like a previously poor diet or poor shoeing, the writer states that as a healthier hoof grows down the ugly will go away, saying stretched white line is no match for healthy well-attached laminae. By contrast, they state deviation is an essential support. “If you trim it away it will rapidly re-appear unless and until its no longer needed to assist in the limb's movement and load-bearing - and while the horse is without it, he will be less comfortable and less capable, especially on tougher surfaces.”
Now a toddler only needs pointing in the right direction, until he develops the muscle memory to walk (skip, run) on his own. Having no preconceived muscle memory (good or bad), no previous imbalances (!) and hopefully enjoying a balanced healthy diet. Can we say the same about those flared or deviated hooves?
As barefoot trimmers it is not uncommon to come across hooves that have been damaged due to poor shoeing, poor hoof balancing at trimming, injury or bad diet. It is not unusual, but also not common, to find an issue that will benefit from being left alone, having put in place other corrective factors like a correct diet and freedom of movement; So are we really leaving it alone?
I find articles like this can be very misleading, implying that many issues will resolve themselves, across the board, without human intervention. Does that mean no dietary changes? Does that mean no imported beaches to make dynamic circuits for them to move on? Or is this another case of re-writing soundness?
One to many videos of horses that are either dishing or knitting or stepping short as they have adapted to the abandoned flares in their hooves is circulating the ethernet. To my mind those are the deviations that the whole horse has had to adapt to, not just the hooves - a timely reminder that you should never just look at the feet, why each horse is assessed for the individual it is, and why we keep records!