vaccination as a tool to control metritis in dairy cows

The objective of this review article was to summarize the most recent clinical field trials that have been published evaluating the use of different types of vaccines against metritis pathogens in dairy cows. metritis is an important disease for the dairy industry globally due to its high prevalence (25–40%), associated economic losses, and animal welfare effects. metritis is most common within 10 days of parturition. metritis is characterized by an enlarged uterus and a watery red-brown fluid to viscous off-white purulent, uterine discharge, which often has a fetid odor. metritis reduces the profit potential of dairy farms because of treatment costs, impaired reproductive performance, and increased involuntary culling. escherichia coli, trueperella pyogenes, prevotella melaninogenica, and fusobacterium necrophorum, utilizing culture-dependent methods, have historically been implicated as the main bacteria associated with uterine infection. the diagnosis and treatment of metritis are inconsistent, which is a concerning situation when considering the global threat of antimicrobial resistance dissemination. various studies have been conducted in recent years to investigate immunizations against metritis pathogens. in the studies, proteins representing major virulence factors of uterine pathogens (fimh, lkta, pyolysin, and plo) and inactivated whole bacterial cells (escherichia coli, fusobacterium necrophorum, trueperella pyogenes, streptococcus uberis, bacteroides, and peptostreptococcus species) have been used to prepare vaccines. vaccines based on recombinant subunit proteins (fimh, plo, and lkta) have been more effective in preventing metritis and improving reproductive performance. in these studies, vaccines were prepared for administration either intravaginally or subcutaneously, and the latter method was more effective. the vaccine development efforts presented in studies are going to become available for dairy producers soon and likely can be an instrumental tool to reduce the metritis burden and antimicrobial use.