Experimental medication of equine ringworm due to Trichophyton equinum var. autotrophicum.

This study rigorously investigates the effectiveness of twelve different medicinal treatments for equine ringworm, a skin disease in horses caused by the fungus Trichophyton equinum var. autotrophicum. It’s discovered that certain treatments yield promising results, but limitations occur when treating many horses, and hair regrowth alone wasn’t found to be conclusive proof of successful treatment.

Selection and Evaluation of Medicaments

• The researchers tested twelve different medicaments to ascertain which were most effective in treating Trichophyton equinum var. autotrophicum, the fungus responsible for causing ringworm in horses.
• Medications evaluated include povidone iodine, thiabendazole ointment, captan ointment, and Burroughs Wellcome Ringworm Ointment. Aqueous washes containing hexetidine or chloramine-T were also considered, as were solutions of lime sulphur and captan. Additionally, nystatin ointment, iodine fortis, Medol, and a proprietary ointment called Queensland Itch Dressing were tested.
• These medicaments were chosen based on previous usage, availability, and potential for effectiveness against the fungal pathogen.

Results and Observations

• Limited success was noted with povidone iodine, thiabendazole ointment, captan ointment, and Burroughs Wellcome Ringworm Ointment. However, the research suggests that these treatments may not be practical for large groups of horses due to factors such as ease of application and cost.
• Hexetidine and chloramine-T, as well as thiabendazole and etisazole suspensions, were considered unsatisfactory as they failed to prevent the isolation of the fungus from lesions for up to 7 and 15 days post-treatment, respectively.
• Solutions of 2.5% lime sulphur and 2% captan were found to be the least effective, with fungus detectable on the lesions for up to 30 days after application.
• Similarly, nystatin ointment, iodine fortis, Medol, and Queensland Itch Dressing were deemed unsatisfactory due to their inability to sufficiently inhibit the fungus.

Implications and Conclusions

• The researchers suggest that mass medication endeavors should focus primarily on preventing the spread of the infection. This conclusion stems from the observation that medication had limited impact on hair regrowth—a commonly-used but potentially inaccurate indicator of healing.
• Both clinical appraisal and a scratch test are recommended for evaluating the treatment progress, rather than relying on hair regrowth alone.
• Thus, the research highlights the need for further development and investigation of cost-effective and efficient treatments for equine ringworm, especially in settings involving treatment of large horse populations.