title: Clinical and radiographic features of contagious ovine digital dermatitis and a novel lesion grading system.
abstract: Contagious ovine digital dermatitis (CODD) is an infectious foot disease of sheep causing severe lameness. Diagnosis is currently made using broad anecdotal descriptions. The aim of this study was to systematically and formally describe the clinical presentation of the disease in terms of (1) a lesion grading system; (2) associated radiographic changes and (3) severity of associated lameness. A five-point lesion grading system was developed and applied to 908 sheep affected by CODD from six farms. Sheep with lesions typical of each grade were euthanased and their feet radiographed. Radiographic abnormalities including soft tissue and bony changes were evident in feet with lesions graded 2-5. In order to quantify the welfare impact of CODD, all the 908 sheep were locomotion scored. Five hundred and eighty-five (64.5% (95% CI 61.4% to 67.6%)) were lame. The locomotion score for affected sheep increased with worsening pathological changes. Once healing had begun the locomotion score decreased. In conclusion the five-point grading system may be used to clinically describe stages of CODD lesions. The radiographic changes revealed examples of deeper pathological changes and there was a strong association between the lesion grading system and locomotion score in affected sheep.
authors: Department of Epidemiology and Population Health, Institute of Infection and Global Health, The University of Liverpool, Leahurst Campus, Neston, Wirral CH64 7TE, UK.
authors: J W
authors: JW
authors: Angell
authors: Department of Veterinary Pathology, School of Veterinary Science, The University of Liverpool, Leahurst Campus, Neston, Wirral CH64 7TE, UK.
authors: R
authors: R
authors: Blundell
authors: Department of Epidemiology and Population Health, Institute of Infection and Global Health, The University of Liverpool, Leahurst Campus, Neston, Wirral CH64 7TE, UK.
authors: D H
authors: DH
authors: Grove-White
authors: Department of Epidemiology and Population Health, Institute of Infection and Global Health, The University of Liverpool, Leahurst Campus, Neston, Wirral CH64 7TE, UK.
authors: J S
authors: JS
authors: Duncan
mesh_terms: D000818:Animals; D058066:Digital Dermatitis / Q000000981:diagnostic imaging* / Q000473:pathology*; D005534:Foot Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D007794:Lameness, Animal; D011859:Radiography; D012720:Severity of Illness Index; D012756:Sheep; D012757:Sheep Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*
keywords: Contagious ovine digital dermatitis; Footrot; Lameness; Pathology; Radiography; Sheep