Comparison of clinical cure rates from footrot and contagious ovine digital dermatitis using zinc sulphate foot bathing and topical oxytetracycline: A randomised trial

Abstract

BackgroundThis study reports the clinical cure rates of topical oxytetracycline and 10% zinc sulphate foot bathing for treatment of interdigital dermatitis (ID), footrot (FR) and contagious ovine digital dermatitis (CODD) in lambs.MethodsThe study was a randomised controlled trial of 75 lambs. Group A (n = 38) was foot bathed daily for 5 days in 10% zinc sulphate for 15 minutes and group B was treated with daily topical oxytetracycline for 5 days. On days 0, 7, 14, 28 and 42, lambs were scored for locomotion and foot lesions were recorded.ResultsThe initial cure rates for ID were 96.20% and 97.00%; for FR, 100% and 95%; and for CODD, 90.09% and 83.33% for zinc sulphate and oxytetracycline, respectively. By day 42, these had changed to 53.16% and 61% for ID; 47.82% and 70% for FR; and 100% and 83.33% for CODD. There were no significant differences in cure rates between the treatments for most time points.LimitationsThe sample size was small, and further studies in larger cohorts and different classes of sheep are required before the findings can be translated into recommendations for clinical practice.ConclusionBoth treatments achieved cure rates that are comparable to reported cure rates using systemic antibiotics and could be an effective alternative.

Is footbathing as effective as antibiotics when treating sheep with footrot or contagious ovine digital dermatitis?

“…Overall, the two treatment protocols did not lead to significantly different cure rates in the lambs studied. 17 However, as noted by the authors, while ID and SFR lesions resolved due to treatment, new lesions also developed because of infections acquired during the study period. Cure rates were, therefore, higher on day two than day 37 because new lesions had developed on the feet by day 37.…”

“…In contrast, cure rates for CODD did not change significantly between day two and day 37. 17 However, there were few cases of CODD in the studied lambs, so this finding should be interpreted cautiously.…”

“…5,15 Additionally, the prevalence of non-infectious foot lesions (granuloma and shelly hoof) has been reported to be higher in flocks that are footbathed routinely. 16 To help provide greater clarity on the efficacy of footbathing, the study by Jackson and colleagues, 17 summarised on p 242 of this issue of Vet Record, aimed to establish and compare the clinical cure rates of a commonly used disinfectant footbath solution (10 per cent zinc sulphate) and a spray-on topical antibiotic preparation (oxytetracycline) for the treatment of ID, SFR and CODD lesions in housed fattening lambs.…”

“…The treatment was repeated on five consecutive days, with the footbath emptied and re-filled each day. 17 However, as the authors note, it may be difficult for farmers to achieve this quality of footbathing routine, as it can be challenging to get sheep to stand in a footbath for long periods, and many farms do not have sufficient facilities for sheep to stand in the dry after, which is important because the chemicals need time to dry on the feet. The lambs were subsequently locomotion scored and observed for ID, SFR and CODD lesions two, nine, 23 and 37 days after the final treatment, and the cure rate at each follow-up visit was calculated as the proportion of feet recorded as affected at the study onset that were no longer affected at the given time point.…”

“…The lambs were subsequently locomotion scored and observed for ID, SFR and CODD lesions two, nine, 23 and 37 days after the final treatment, and the cure rate at each follow-up visit was calculated as the proportion of feet recorded as affected at the study onset that were no longer affected at the given time point. 17 Since the lambs had been preselected based on lameness identified by the farmer, the prevalence of lameness in the population was initially high (66.7 per cent), with 66 of the 75 lambs affected by ID, 47 affected by SFR and 16 affected by CODD. Cure rates in the footbathing and antibiotic groups were 96.2 per cent and 97.0 per cent for ID, 100 per cent and 95.0 per cent for SFR, 90.1 per cent and 83.3 per cent for CODD and 50.0 per cent and 59.0 per cent for lameness, respectively, two days after the final treatment.…”