I am a firm believer that "research" can a horse owner's best friend. Many years a go I bought a hard-backed book titled Horse Owner's Veterinary Handbook
authored by James M. Giffin,MD & Tom Gore, DVM.
I do believe I may have found a correlation of the Deep Sulcus Thrush and Navicular Disease. I quote, "Infection can penetrate sensitive laminae of the foot, infect the digital cushion and damage the tendons(unquote)." Navicular Disease, and again I quote, "The navicular bone transmits a considerable portion of the weight of the horse. In doing so it is forced backward against the deep flexor tendon. Injurious contact between these structures is prevented by the interposition of a bursa(senovial fluid sac, my insertion). But as the bursa becomes inflamed, the bone and tendon are no longer protected. Traumatic changes then occur in the tissues surrounding the navicular bone.(unquote)." This info credited to the above source in first paragraph.
More "food for thought" so to speak.
Any thoughts Welcomed no matter in the positive or negative of my research.