A Randomised Non-inferiority Trial on the Effect of an Antibiotic or Non-antibiotic Topical Treatment Protocol for Digital Dermatitis in Dairy Cattle

Abstract

Objective: Investigation of the therapeutic effect of a protocol using non-antibiotic Intra Epidine (IE) spray containing copper and zinc chelate on M2 digital dermatitis (DD) lesions compared to a treatment protocol using antibiotic chlortetracycline (CTC) spray for non-inferiority testing. Background: Digital dermatitis (DD) is an infection in dairy cattle which frequently results in lameness. A common individual treatment for DD in Europe is a topical administration of antibiotic CTC spray. Given the important objective to minimise antibiotic use in order to prevent selection for antibiotic resistance, there is a need for effective non-antibiotic treatments for common animal diseases. Evidentiary value: This clinical trial on commercial farms with registered products is valuable for all veterinary practitioners interested in the quantitative curative effects of treatments forDD. Methods: Professional hoof trimmers trimmed hind legs of 944 cows from nine dairy herds. All legs with DD M2 lesions were included and randomly assigned to a treatment protocol with IE spray or CTC spray according to the label instructions from the manufacturers. At the end of the study 231 individual legs, one per cow, in seven herds were eligible for analysis. Clinical improvement was defined as the transition of the clinical most relevant ulcerative M2 lesion to any other less severe lesion stage at 10 days after the start of the treatment. Results: The overall individual leg clinical improvement rate of IE spray (86.8%) was higher compared to CTC spray (47.9%). The herd adjusted odds ratio for clinical improvement was 8.2 (95% CI 4.2 – 15.7) for IE spray versus CTC spray with an estimated Relative Risk of 1.9. Conclusion: In conclusion, the IE treatment protocol was non-inferior but more effective than the CTC treatment protocol to clinically improve DD M2 lesions.