Pathology of CODD

The bacteria implicated in CODD: Treponema spp. can be seen under a microscope in affected feet using a special stain. They appear as black spiral shapes (arrow) and can clump together forming mats:

CODD Bacteria

In feet with CODD the pathological changes are severe, causing the hoof horn to slough off. The inflammation caused goes deep into the tissues and can in some cases affect the bone in the foot as shown in the x-ray image:

Pathology of CODD - radiograph

More information on the pathological changes seen in affected feet can be found in following two published papers:

Angell, J.W., Blundell, R., Grove-White, D.H., and Duncan, J.S., (2015). Clinical and radiographic features of contagious ovine digital dermatitis and a novel lesion grading system. Veterinary Record 176(20), 521-523

Angell, J.W., Crosby-Durrani, H.E., Duncan, J.S., Carter, S.D., Blundell, R. (2015).  Histopathological Characterization of the Lesions of Contagious Ovine Digital Dermatitis and Immunolabelling of Treponema-like Organisms.  Journal of Comparative Pathology 153(4), 212-226