Circumferential hoof clamp method of lameness induction in the horse.

The research paper assesses a method using a hoof clamp to induce temporary lameness in horses. This method enabled the researchers to study lameness in a controlled manner. Following the releasing of the clamp, lameness was not immediately reversed, but horses returned to their initial state in about three days.

Methodology

• A method was devised to induce lameness in horses in a controlled way. This was achieved through use of a circumferential hoof clamp applied to the forelimbs of eight horses.
• The clamp was tightened to a point where it caused noticeable lameness in the chosen limb.
• To measure this induced lameness objective measurements such as peak vertical forces and vertical impulses were recorded by a force plate.
• The whole procedure was also video-recorded, the videos of which were subsequently evaluated by blinded observers to determine subjective lameness on a scale of 0 to 5.

Results

• The method was consistent and effective in inducing controlled and reversible lameness in all eight study horses.
• Changes in peak vertical forces were used to confirm induced lameness. A statistically significant decrease from the baseline level in the peak vertical force was observed when the clamp was tightened, which established physical evidence of lameness.
• The induced lameness was also confirmed subjectively by elevated scores (from 0 at the baseline to 2 during lameness) given by the blinded observers evaluating the video recordings.

Reversibility of Induced Lameness

• The clamps were loosened after the stage of induced lameness. This was followed by assessments to determine whether the lameness was fully reversible.
• It was found that the lameness did not immediately reverse upon loosening of the clamp, with median lameness scores still indicating some degree of lameness (1.5).
• However, noticeable lameness reduced and horses returned to their initial state in about three days after the clamp removal. This was indicated by the score reverting close to the initial baseline (median score of 0.5).