4258

ISURF #4258 describes a method for inducing papillomatous digital dermatitis (PDD) in cattle, an important disease for the US dairy industry that is leading cause of lameness.  Also disclosed are a number of bacterial isolates that are used to induce the disease model for this polymicrobial infection.  Advantages of this technology include lower cost, more faithful and consistent replication of lesions seen with the natural disease, and rapid disease induction.

Digital dermatitis (DD) is an economically important polymicrobial disease process of dairy cattle that, despite 35 years of research, remains etiologically undefined. It is the leading cause of lameness in US dairy cattle. In addition to the cost associated with treatment and lost production, it represents a significant welfare concern for the industiy. For these reasons, lameness, and specifically DD, was ranked as the top priority by Daily Industry Stakeholders at the 2010 USDA ARS-NIFA Anitnal Health Research Planning Workshop. Although the disease  is responsive to antibiotics, a definitive bacterial cause has not been identified. Treponema spp. are regularly isolated from DD lesions, however attempts to induce classic disease lesions with pure culture of these microorganisms remain universally unsuccessful. Based on these findings, and the lack of efficacy of Treponema based vaccines, it is widely believed that the disease is polybacterial in nature. The identity of microorganisms that work in concert with Treponema spp. to cause the clinical presentation of DD in cattle has remained unknown. Lack of this knowledge is an inportant problem because it prevents the development of effective intervention strategies that target the causative agents of DD. One important tool for studying this disease process is the development of a consistent model of disease induction that results in lesions characteristic of the naturally occurring lesions. Such a model will allow for indepth study of the disease pathogenesis, experimental studies to try and fulfill identification of causative organisms and most importantly a model useful for testing experimental interventions (vaccines, treatments, prevention etc). This disclosure describes a novel induction method useful for inducing digital dermatitis lesions that appear consistent with the natural disease process. Furthermore, this method results in reasonably quick induction in the characteristic site of lesion development. Previous induction methods that have been attempted either do not provide consistent results or induce lesions that are not consistent with natural disease.

• Lesions consistent with the natural disease process

• Availability of isolates

• Potential for marked improvement vs. current approaches

Veterinary Research

Animal Model Protocol, Diagnostic, Therapeutic And Vaccine Against Digital Dermatitis, US 2016/0256575