The evaluation of isoxsuprine hydrochloride for the treatment of navicular disease: a double blind study.

This research assessed the effectiveness of isoxsuprine hydrochloride for treating navicular disease in horses using a randomised, double-blind clinical trial. The study found significant improvements in clinical assessment scores for horses treated with isoxsuprine hydrochloride, with no dose-related differences in response.

Explanation of the Research

• The researchers used a randomized double-blind clinical trial to evaluate the effectiveness of isoxsuprine hydrochloride on navicular disease in horses. This is a powerful study design as it allows for unbiased allocation of treatment and ensures that neither the researchers nor the subjects knew which treatment was being received, thereby ruling out placebo effect.
• The trial involved 28 horses that were randomly assigned to receive either a placebo (0.0 mg/kg of body weight), or one of three doses of isoxsuprine hydrochloride (0.6 mg/kg, 1.2 mg/kg, or 1.8 mg/kg of body weight).

Key Findings

• It was found that horses treated with isoxsuprine hydrochloride (a total of 22 horses) showed significant improvements in their clinical assessment score when compared to the control group of 6 horses that received the placebo. This indicates that the drug had a positive effect on treating navicular disease symptoms.
• Interestingly, the study found no dose-related differences in the response of horses to the treatment. This suggest that all doses of isoxsuprine hydrochloride trialed were equally effective at improving clinical scores, so increasing the dose does not necessarily increase effectiveness.
• Finally, the study found no correlation between the radiological evidence of the extent of navicular disease and severity of lameness, or the response to treatment. This may suggest that the visible severity of the disease may not directly relate to how much the disease is affecting the horse or to how effectively the horse responds to treatment.