Although a clinical history of febrile illness accompanied by hemorrhagic enteritis and anorexia may be suggestive in either calves or adults, there is a sufficient differential diagnosis list in both age groups that diagnostic sampling must be performed. manifestations of contamination, with pneumonia being a common manifestation of Dublin contamination in calves. ? Definitive diagnosis is based on detection of the organism through aerobic culture of feces or detection of genetic material from the bacteria via polymerase chain reaction techniques. ? Fluid therapy is the mainstay of treatment for cattle with enteric salmonellosis; antimicrobial therapy remains controversial. ? Larger herd size, crowded husbandry, free stall housing, and purchase of replacement animals contribute to an increased propensity for exposure to contaminated manure, the LAMC1 major source of contamination on dairies. Introduction As an infectious, contagious pathogen is probably rivalled by only bovine viral diarrhea computer virus in its ability to cause such a variety of clinical problems in dairy cattle. Enteric, septicemic, and reproductive diseases are all possible manifestations of contamination and, Exemestane although reproductive losses are only of concern in sexually mature females, enteric disease can be seen in susceptible cattle at any age from true neonates through adulthood. The increasing prevalence in recent years of the host adapted serotype serotype Exemestane Dublin, conventionally referred to by the abbreviated title of Dublin, has added a new, and highly challenging, facet to salmonellosis on many modern dairies. The ability to establish lifelong contamination, characterized by an asymptomatic carrier status, with intermittent periods of bacteremia and intermittent shedding, challenges control of this serotype. Enteric contamination with other nonChost-adapted serotypes, particularly in calves, can also be associated with true bacteremia, sepsis, and high mortality rates. No current discussion of bovine salmonellosis could be complete without acknowledging the increasing public health concern regarding its relevance as an important zoonosis, the risk that contaminated dairy and dairy beef products can pose to human health, and, just as important, the reality that increasing antimicrobial resistance among zoonotic enteric pathogens such as brings the use of antimicrobials by veterinarians and suppliers under ever stricter scrutiny. Etiology and taxonomy is usually a genus of gram-negative, facultative anaerobic bacteria that belong to the family of Enterobacteriaceae. There are 2 recognized species within the genus: and can be further divided into 6 subspecies, subspecies being the most relevant in dairy cattle.1 More than 2500 serovars (serotypes), differentiated by their antigenic composition, have been identified. Serovars are based on the Exemestane somatic (O), flagellar (H), and capsular (Vi) antigens.2 Most human and veterinary diagnostic laboratories have phenotypically divided isolates into serogroups based on detection of the O lipopolysaccharide and H flagellar antigens, historically by agglutination methods.2, 3 Although these traditional serotyping techniques have formed the basis Exemestane of human and veterinary diagnostic practice for salmonellosis for several decades, they are labor intensive and time consuming, typically taking at least 48?hours.4 With the advent of more advanced molecular diagnostic methods, genetic approaches to serotyping are beginning to supercede traditional tests. In general, these methods use 1 of 2 types of targets for serotype determination, the first are indirect targets, which use random surrogate genomic markers known to be associated with certain serotypes, and the second method uses direct targets requiring the use of highly specific genetic determinants of a particular serotype.5 The latter typically involve the gene cluster responsible for O somatic group antigen synthesis6 and the Exemestane and genes encoding the 2 2 flagellar antigens of isolates.4, 5 The hope is that, with diminishing costs and continued refinement, more rapid, accurate genoserotyping will improve diagnostic and surveillance efforts for both public health and veterinary purposes.8 Most commonly, clinical bovine isolates have been divided by their O antigens,.