Quantitative assessment of intravenous regional limb perfusion of tiludronate as an adjunctive treatment for lameness caused by navicular syndrome in horses.

This research examines the effectiveness of two IV regional limb perfusion protocols involving the drug tiludronate, for treating navicular syndrome-induced lameness in horses. It concluded that while no significant improvement was observed over the conventional therapy of therapeutic shoeing and anti-inflammatory injections into the distal interphalangeal joint, horses treated with a higher dose (0.2 mg/kg) of the drug were less lame after 120 days.

Methods and Procedures

• The study involved 15 horses with identified bilateral forelimb navicular syndrome. Horses with this condition typically present with lameness due to inflammation and degeneration of the navicular bone in their hooves.
• At the start of the study, all horses underwent standard treatment for the condition, which included therapeutic shoeing and an anti-inflammatory injection into the distal interphalangeal joint (DIPJ) of both forelimbs.
• After a fortnight, the horses were divided into three groups and treated with either a low-dose (0.1 mg/kg) tiludronate; a high-dose (0.2 mg/kg) tiludronate; or a saline (placebo) solution. The procedure was repeated on the 24th and 34th day.
• Lameness severity was evaluated before and after the initial shoeing, and then on days 14, 34, 60, and 120 through both subjective assessments and force plate analysis, an objective measurement of lameness by determining the peak vertical ground reaction force (PVGRF).

Findings and Results

• The PVGRF showed a general increase for all horses after 14 days, indicating an initial improvement in lameness.
• No significant difference in lameness scores or PVGRF was observed within the treatment groups at the various time points.
• However, by day 120, the mean PVGRF for combined forelimbs (CFL) was higher in the high-dose tiludronate group than in the low-dose group or the placebo group, indicating horses on the higher dose were less lame after four months.

Interpretation and Clinical Relevance

• The tiludronate treatment, at either dose, did not show a marked improvement in lameness in horses with navicular syndrome over conventional therapeutic shoeing and anti-inflammatory injections at the time periods assessed.
• Nevertheless, the results suggest that the higher dosage of tiludronate may have a long-term benefit (after 120 days) in mitigating the lameness caused by navicular syndrome in horses.
• This finding may help guide further research to establish the effectiveness and appropriate dosage of tiludronate for treating navicular syndrome in horses.