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

BACKGROUND: This 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. METHODS: The 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. RESULTS: The 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. LIMITATIONS: The 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. CONCLUSION: Both treatments achieved cure rates that are comparable to reported cure rates using systemic antibiotics and could be an effective alternative.

Impact of research on contagious ovine digital dermatitis on the knowledge and practices of UK sheep farmers and veterinarians.

BACKGROUND: Contagious ovine digital dermatitis (CODD) is a common foot disease of sheep which causes a severe form of lameness and can be difficult to control. Recent research has provided evidence-based guidance on diagnosis, treatment and farm management control. The aim of this study was to determine the uptake of this guidance on the knowledge and practices of UK sheep farmers and veterinarians and identify priorities for future research. METHODS: Data were collected in 2019-2020 by electronic surveys of UK sheep veterinarians and farmers distributed through sheep industry organisations and social media. RESULTS: Two hundred eight-four sheep farmers and 77 veterinarians responded to the surveys. Fifty-two per cent of farmers and 70% of vets considered that their management of CODD had improved as a direct result of recent research evidence on the disease. The principle areas improved for both sectors were biosecurity advice and use of antibiotic treatments. Farmers and veterinarians reported that the priorities for future research should be in therapeutics, vaccine development and the understanding of disease transmission. CONCLUSION: There has been strong uptake of recent evidence-based veterinary medicine by farmers and veterinarians for the management of CODD, particularly in the areas of biosecurity and responsible antibiotic use.

In vitro susceptibility of contagious ovine digital dermatitis associated Treponema spp. isolates to antimicrobial agents in the UK.

BACKGROUND: Contagious ovine digital dermatitis (CODD) is an important cause of infectious lameness in sheep in the UK and Ireland and has a severe impact on the welfare of affected individuals. The three treponemal phylogroups Treponema medium/Treponema vincentii-like, Treponema phagedenis-like and Treponema pedis spirochaetes have been associated with clinical CODD lesions and are considered to be a necessary cause of disease. There are scant data on the antimicrobial susceptibility of the treponemes cultured from CODD lesions. OBJECTIVE: The aim of this study was to determine in vitro the miniumum inhibitory concentration/ minimum bactericidal concentration (MIC/MBC) of antimicrobials used in the sheep industry for isolates of the three CODD associated treponeme phylogroups T. medium/T. vincentii-like, T. phagedenis-like and T. pedis. ANIMALS: Twenty treponeme isolates; from 19 sheep with clinical CODD lesions. METHODS: A microdilution method was used to determine in vitro the MIC/MBC of 10 antimicrobial agents for 20 treponeme isolates (five T. medium/T. vincentii-like, 10 T. phagedenis-like and five T. pedis). The antimicrobials tested were penicillin G, amoxicillin, oxytetracycline, tilmicosin, lincomycin, spectinomycin, tylosin, tildipirosin, tulathromycin and gamithromycin. RESULTS: The treponeme isolates tested showed low MICs and MBCs to all 10 antimicrobials tested. They were most susceptible to gamithromycin and tildipirosin (MIC90: 0.0469 mg/L), and were least susceptible to lincomycin, spectinomycin and oxytetracycline (MIC90: 48 mg/L, 24 mg/L and 3 mg/L, respectively). CONCLUSIONS: These data are comparable to in vitro antimicrobial susceptibility data for treponemes cultured from bovine digital dermatitis lesions. Dependent on local licensing, penicillin and tilmicosin appear to be the best candidates for future in vivo studies.