Field evaluation of prophylactic and therapeutic effects of a vaccine against (papillomatous) digital dermatitis in dairy cattle on two California dairies

Abstract

The objectives of this study were to determine the prophylactic and therapeutic effects of a Treponema bacterin against papillomatous digital dermatitis ((P)DD) in lactating dairy cows from 2 California dairies and to compare the serological response to the Treponema bacterin between vaccinate and placebo groups of cows. A total of 1160 Holstein-Friesian cows were used in this study. The cows were grouped according to treatment (vaccinated or placebo) and visible (P)DD lesion status prior to treatment. 120 cows with no visible lesions prior to treatment were bled for serological evaluation. Monthly visual and serological evaluations were performed before and after the treatment for 6 months. Comparison of monthly proportion of cows between groups of vaccinates and placebos showed insignificant prophylactic or therapeutic effects due to the Treponema bacterin. Results were also insignificant when monthly proportions of cows were stratified by lactation groups or for only those cows present at every monthly observation and stratified by lactation groups. ELISA titres of the 120 cows bled prior to treatment showed that 43% of the cows had positive titres, indicating prior exposure to Treponema spp. Comparison between monthly proportions of vaccinates and placebo cows that had no visible (P)DD lesions, and which had negative serological titres to (P)DD-associated Treponema spp. antigens prior to treatment, showed that a significantly higher proportion of vaccinates developed a positive serological state during the 1st, 2nd and 3rd months after treatment.