Use of force plate analysis to compare the analgesic effects of intravenous administration of phenylbutazone and flunixin meglumine in horses with navicular syndrome.

The study analysed the effectiveness of two pain-relieving drugs, flunixin meglumine and phenylbutazone, on horses affected with navicular syndrome. Researchers used a force-plate analysis to come to the conclusion that both medicines provided significant improvement in lameness compared to a saline solution.

Objectives of the study

• The main objective of this study was to understand the analgesic (pain-relieving) effects of the two drugs, namely: flunixin meglumine and phenylbutazone, on horses diagnosed with navicular syndrome.
• Another aim of the research was to employ the use of a force plate analysis to measure the efficacy of these drugs.
• The study also intended to compare the two medications’ effects against using a saline solution.

Methods and Procedures

• Involvement of 12 horses with navicular syndrome that were otherwise clinically normal.
• Administration of flunixin (1.1 mg/kg), phenylbutazone (4.4 mg/kg), or physiologic saline (0.9% NaCI; 1 mL/45 kg) solution iv once daily for 4 days.
• Use of a 14-day washout period between treatments so each horse underwent three different treatments.
• Evaluation of horses before treatment (baseline), and at 6, 12, 24, and 30 hours post the fourth dose of each treatment.
• Use of the American Association of Equine Practitioners lameness scoring system to evaluate treatment effects, and a force plate for measuring peak vertical force of the forelimbs.

Main Findings

• Both flunixin and phenylbutazone showed significant improvement in lameness from initial values, faring better than control horses that received only the saline solution. This improvement was visible at 6, 12, and 24 hours after the last dose of treatment.
• There was no significant difference observed in the horses treated with either of the two drugs, indicating comparable effects.
• The effect of both flunixin and phenylbutazone lasted for at least 24 hours after the final dose.

Conclusions

• The results suggest that for horses affected with navicular syndrome, standard clinical doses of flunixin and phenylbutazone yield a marked improvement in lameness compared to horses treated with a saline solution, and the effect lasted for at least a day after dosage.
• Both flunixin meglumine and phenylbutazone showed similar pain-relieving effects in horses with this condition, thereby suggesting their use as effective analgesics for horses suffering from navicular syndrome.