Seedy Toe, sometimes called White Line Disease, is the necrosis of the sensitive laminae, usually on the anterior wall of the hoof. It can however affect all distal areas of the laminae, extending proximally towards the coronary band. The condition is caused by cracks in the white line, leading to infection and chronic laminitis with separation of the laminae in the area of the white line, usually at the toe. In some cases, anaerobic fungi have also been incriminated.
- A horse with seedy toe will generally show slight to moderate lameness although this is not seen in every case.
- A chalky, crumbly white line region, which can be easily gouged out with a foot knife, will be present on examination of the foot.
- The hollow behind the adjacent hoof wall may show grit and other foreign matter.
- Overt sepsis is occasionally present, with a discharging tract at the coronary band proximal to the region affected.
How is seedy toe diagnosed?
Diagnosis is confirmed by the characteristic clinical signs listed above. In some cases a lateral radiograph (x-ray) will be taken and will clearly show air and foreign matter wedged into the area between the wall and the pedal bone.
Small areas of seedy toe can be pared back to healthy tissue with a hoof knife and, if the defect is spotlessly clean, it can be packed with synthetic filler. If not clean, the cavity will need to be tightly packed with a swab soaked in povidone-iodine or Metronidazole. The swab will need to be replaced daily.
More severe cases require the wall over the seedy portion to be completely removed and a small area of wall removed back to sound laminar tissue, either by a vet or a skilled farrier. The defect is not filled permanently until all risk of haemorrhage is past and the area is clean and infection free.
Some defects are very wide and as high as the coronet and these need to be extensively debrided, after a shoe with supportive side clips has been fitted to the foot to stabilise the distal margin. The shoe is then removed and the defects are debrided
Once all the necrotic and infected tissue has been removed the defect can be filled with an acrylic filler, the shoe reset and the horse rested in a stable. The animal should have only light walking for two weeks following treatment. The shoe should be regularly reset every four weeks and a close watch kept on the repair patch to make sure it remains firm and uninfected.