1The aims of this study were to update the prevalence of lameness in sheep in England 2 and identify novel risk factors. A total of 1260 sheep farmers responded to a postal 3 survey. The survey captured detailed information on the period prevalence of 4 lameness from May 2012 -April 2013 and the prevalence and farmer naming of 5 lesions attributable to interdigital dermatitis (ID), severe footrot (SFR), contagious 6 ovine digital dermatitis (CODD) and shelly hoof (SH), management and treatment 7 of lameness, and farm and flock details. 8The global mean prevalence of lameness fell between 2004 and 2013 from 10.6% to 9 4.9% and the geometric flock mean period prevalence of lameness fell from 5.4% 10 (95% CL: 4.7-6.0%) to 3.5% (95% CI: 3.3%-3.7%). In 2013, more farmers were 11 using vaccination and antibiotic treatment for ID and SFR and fewer farmers were 12 using foot trimming as a routine or in therapeutic treatment than in 2004. 13Two over-dispersed Poisson regression models were developed with the outcome the 14 period prevalence of lameness, one investigated associations with farmer estimates of 15 prevalence of the four foot lesions and one investigated associations with 16 management practices to control and treat lameness and footrot. A prevalence of ID 17 >10%, SFR >2.5% and CODD >2.5% were associated with a higher prevalence of 18 lameness compared with those lesions being absent, however, the prevalence of SH 19was not associated with a change in risk of lameness. 20 A key novel management risk associated with higher prevalence of lameness was the 21 rate of feet bleeding / 100 ewes trimmed / year. In addition, vaccination of ewes once 22 per year and selecting breeding replacements from never-lame ewes were associated 23 with a decreased risk of lameness. Other factors identified as associated with a lower 24 3 risk of lameness, for the first time in a random sample of farmers and a full risk 25 model, were recognising lameness in sheep at locomotion score 1 compared with 26 higher scores, treatment of the first lame sheep in a group compared with >5, 27 treatment of lame sheep within 3 days, ease of catching lame sheep and quarantine 28 for >21 days. A previously known factor associated with a lower risk of lameness 29 was footbathing to prevent ID. We conclude that the prevalence of lameness in sheep 30 in England has fallen and that this might be in part because of increased uptake of 31 managements previously reported as beneficial to control lameness. Routine foot 32 trimming should be avoided. 33 4

Footrot is an infectious bacterial disease of sheep that causes lameness. The causal agent is Dichelobacter nodosus. There is debate regarding the role of Fusobacterium necrophorum in disease initiation. This research used an observational longitudinal study of footrot, together with quantitative PCR (qPCR) of bacterial load of D. nodosus and F. necrophorum, to elucidate the roles of each species in the development of disease. All feet of 18 a priori selected sheep were monitored for five weeks assessing disease severity (healthy, interdigital dermatitis (ID) and severe footrot (SFR)) and bacterial load. A multinomial model was used to analyse these data.Key unadjusted results were that D. nodosus was detected more frequently on feet with ID, whereas F. necrophorum was detected more frequently on feet with SFR. In the multinomial model, ID was associated with increasing log10 load of D. nodosus the week of observation (OR = 1.28 (95% CI = 1.08–1.53)) and the week prior to development of ID (OR = 1.20 (95% CI = 1.01–1.42). There was no association between log10 load2 of F. necrophorum and presence of ID (OR = 0.99 (95% CI = 0.96–1.02))). SFR was associated with increasing log10 load of D. nodosus the week before disease onset (OR = 1.42 (95% CI = 1.02–1.96)) but not once SFR had occurred. SFR was positively associated with log10 load2 of F. necrophorum once disease was present (OR = 1.06 (95% CI = 1.01–1.11)). In summary, there was an increased risk of increasing D. nodosus load the week prior to development of ID and SFR and during an episode of ID. In contrast, F. necrophorum load was not associated with ID before or during an episode, and was only associated with SFR once present. These results contribute to our understanding of the epidemiology of footrot and highlight that D. nodosus load plays the primary role in disease initiation and progression, with F. necrophorum load playing a secondary role. Further studies in more flocks and climates would be useful to confirm these findings. This study identifies that D. nodosus load is highest during ID. This supports previous epidemiological findings, which demonstrate that controlling ID is the most effective management strategy to prevent new cases of ID and SFR.

Background: Internationally, foot trimming is used by most farmers, and parenteral antibacterials by some, to treat sheep with footrot. Nonsteroidal anti-inflammatory drugs (NSAID) are sometimes used. No clinical trials have compared these treatments.Objectives: To investigate the above treatments on time to recovery from lameness and foot lesions in sheep with footrot. Animals: Fifty-three sheep with footrot on a commercial farm in England. Methods: In a randomized factorial design, the sheep were allocated to 6 treatment groups. The treatments were oxytetracycline spray to all sheep (positive control) and one or more of parenteral administration of long-acting oxytetracycline, flunixine meglumine, and foot trimming on day 1 or 6 of diagnosis. Follow-up was for 15 days. Time to recovery from lameness and lesions was investigated with discrete-time survival models.Results: There was significant association (P o .05) between recovery from lameness and lesions. Sheep receiving antibacterials parenterally recovered faster from lameness (odds ratio [OR] Conclusions and Clinical Importance: If foot trimming on day 1 or 6 of diagnosis was stopped and parenteral antibacterials were used, then over 1 million sheep/annum lame with footrot in the United Kingdom would recover more rapidly with benefits to productivity. Globally, this figure would be much higher.