Seedy toe is a separation of the horses hoof wall from the underlying sensitive laminae at the white line, resulting in a cavity which fills with crumbling dirt, horn and debris and is prone to associated infection.
It can occur as a complication of chronic laminitis with rotation and sinking of the pedal bone (P3 or distal phalanx), followed by secondary infection. It can also occur in non-laminitic feet with long toe/low heel conformation, where the hoof wall separation and subsequent infection are the primary features. It may also occur in feet with poor dorso-palmar (front to back) balance and as a sequel to 'club foot' and may be predisposed by poor quality hoof horn.
Infection with anaerobic bacteria and yeasts, which are common hoof contaminants and an important feature in all forms of seedy toe, can liquefy hoof keratin, separating the sensitive laminae, progressing to rotation of the pedal bone as in laminitis.