Equine laminitis: ultrastructural lesions detected 24-30 hours after induction with oligofructose.

This research study investigates the earliest signs of equine laminitis, a disease that affects horses’ hooves, after inducing the disorder with oligofructose. It was observed that changes identified via a technique known as transmission electron microscopy (TEM) were noticeable within 24 hours post induction, suggesting that preventative treatments for the disease should ideally be administered before lameness signs develop.

Methods

• The research involved eight adult Standardbred horses that were clinically normal. These subjects were randomly split into two groups – treatment and sham treatment (control) group.
• The horses in the treatment group received a dose of oligofructose (10 g/kg bodyweight). They were then euthanized as they started shifting weight from one foot to other, which is the earliest noted sign of lameness during movement and turning. This was observed within 24-30 hours after the induction.
• The control group, on the other hand, were dosed with water and euthanized after 48 hours.
• Lamellar tissues from the front feet of the horses in both groups were harvested and processed for an ultrastructure study using a technique known as transmission electron microscopy (TEM).

Results

• TEM examination revealed significant changes in the basement membrane zone, characterized by excessive waviness, and the pointed tips of some secondary epidermal lamellae, a typical indicator of laminitis.
• It was also noted that the number of hemidesmosomes (structural components that function in the adhesion of cells to the extracellular matrix) per micrometer of basement membrane was decreased, with their distance from the centre of the lamina densa of the basement membrane also increased.

Conclusions

• The findings suggest that the lesions typical of laminitis can be detected as early as 24 hours after induction by oligofructose.
• The destruction of the hoof lamellar interface begins to occur in the initial 24 hours, prompted by events in the hindgut post dosing. Therefore, any prevention and treatment strategies should be implemented before the onset of lameness to prove efficacious.