Bovine digital dermatitis in Victoria, Australia

Introduction
Bovine Digital Dermititis is widespread around the World^1-10. In Australia, until recently limited published reports or research about DD have been available, except for one single suspected case in 1996, near Brisbane¹¹, and cases of DD in one herd in Victoria, Australia¹². However, since 2015, there has been an ongoing study in Queensland investigating the prevalence of DD in that state¹³. Prior to our study, a pilot study among 13 herds in Victoria, Australia was conducted. The herds were examined for DD and 100% of these herds were found to be positive, with a mean herd-level prevalence of 19.11%¹⁴. The prevalence and causative subspecies of Treponema of DD are not yet clear in Australia and this information is important to aid in the development of education, treatment methods and preventive measures. The objectives of this study were to estimate the prevalence of DD in Victoria, Australia, and to investigate which Treponema-species or other bacteria are associated with typical DD-lesions. 

Materials and Methods
Five researchers from the University of Melbourne investigated the prevalence of DD and collected samples from DD-like lesions. Examination and sampling of limbs was undertaken at three knackeries in Victoria, Australia. A knackery is a processing facility for deceased cattle that are not fit for human consumption or for transportation, and the reason for culling these cows was not recorded. Limbs were classified as normal (N), active DD-lesion (A), dried or chronic DD-lesion (D) or suspected case of DD (S). A total of 823 cows were examined. Six skin biopsies were taken at each knackery, from which DNA was extracted for diversity profiling. Histochemical staining of samples were performed on eight of the skin biopsies. […]