**Salmonella Dublin in Dairy Cattle** Salmonella enterica serovar Dublin (S. Dublin) is a host-adapted bacterium that primarily affects cattle, causing severe health issues and economic losses in dairy facilities. S. Dublin is a zoonotic bacterium that can lead to severe illness in humans, including hospitalizations and mortality. The bacterium is difficult to control and eradicate from herds, as it can be shed by clinically normal animals. This review provides an overview of S. Dublin as a pathogen in dairy facilities, the risk factors associated with infection, and current strategies for prevention and control. **Prevalence and Impact:** - S. Dublin is prevalent in dairy farms worldwide, with varying rates across different countries. - In the US, S. Dublin has become one of the most important multi-drug resistant (MDR) bacteria in cattle. - The bacterium can cause severe disease in young calves, leading to high morbidity and mortality, and can affect mature animals, reducing their performance. - S. Dublin has been identified as the most common serotype among bovine Salmonella isolates in several countries, including the US, Germany, and the UK. **Pathogenesis and Clinical Signs:** - S. Dublin invades the digestive tract and can disseminate systemically, causing septicemia. - Clinical signs are more severe in calves, with acute presentations including pneumonia, respiratory distress, and hyperthermia. - Chronic infections in calves can lead to growth retardation, loose stool, and lameness. - Adult animals may experience fever, bloody diarrhea, and in extreme cases, death. **Antimicrobial Resistance:** - S. Dublin has a high prevalence of MDR, which complicates treatment and increases costs and mortality. - The bacterium is resistant to multiple classes of antimicrobial drugs, including ampicillin, chloramphenicol, and tetracycline. - Antimicrobial susceptibility patterns have remained largely unchanged, with only a few drugs remaining effective. **Economic Impact:** - The financial impact of S. Dublin includes treatment costs, reduced milk yield, abortion, culled animals, and increased working hours during outbreaks. - Latent carriers, which are asymptomatic but periodically shed the bacterium, contribute to the endemicity of the pathogen. **Risk Factors:** - Host factors, such as immune status and age, play a crucial role in infection. - Latent carriers, defined as animals with persistent infection without clinical signs, are a significant source of infection. - Management practices, including poor hygiene, stress during calving, and contact with infected animals, increase the risk of infection. - Environmental factors, such as contamination from neighboring facilities and surface water, also contribute to the spread of S. Dublin. **Diagnosis and Treatment:** - Bacteriological culture and polymerase chain reaction (PCR) are used to detect S. Dublin. - Treatment focuses on supportive**Salmonella Dublin in Dairy Cattle** Salmonella enterica serovar Dublin (S. Dublin) is a host-adapted bacterium that primarily affects cattle, causing severe health issues and economic losses in dairy facilities. S. Dublin is a zoonotic bacterium that can lead to severe illness in humans, including hospitalizations and mortality. The bacterium is difficult to control and eradicate from herds, as it can be shed by clinically normal animals. This review provides an overview of S. Dublin as a pathogen in dairy facilities, the risk factors associated with infection, and current strategies for prevention and control. **Prevalence and Impact:** - S. Dublin is prevalent in dairy farms worldwide, with varying rates across different countries. - In the US, S. Dublin has become one of the most important multi-drug resistant (MDR) bacteria in cattle. - The bacterium can cause severe disease in young calves, leading to high morbidity and mortality, and can affect mature animals, reducing their performance. - S. Dublin has been identified as the most common serotype among bovine Salmonella isolates in several countries, including the US, Germany, and the UK. **Pathogenesis and Clinical Signs:** - S. Dublin invades the digestive tract and can disseminate systemically, causing septicemia. - Clinical signs are more severe in calves, with acute presentations including pneumonia, respiratory distress, and hyperthermia. - Chronic infections in calves can lead to growth retardation, loose stool, and lameness. - Adult animals may experience fever, bloody diarrhea, and in extreme cases, death. **Antimicrobial Resistance:** - S. Dublin has a high prevalence of MDR, which complicates treatment and increases costs and mortality. - The bacterium is resistant to multiple classes of antimicrobial drugs, including ampicillin, chloramphenicol, and tetracycline. - Antimicrobial susceptibility patterns have remained largely unchanged, with only a few drugs remaining effective. **Economic Impact:** - The financial impact of S. Dublin includes treatment costs, reduced milk yield, abortion, culled animals, and increased working hours during outbreaks. - Latent carriers, which are asymptomatic but periodically shed the bacterium, contribute to the endemicity of the pathogen. **Risk Factors:** - Host factors, such as immune status and age, play a crucial role in infection. - Latent carriers, defined as animals with persistent infection without clinical signs, are a significant source of infection. - Management practices, including poor hygiene, stress during calving, and contact with infected animals, increase the risk of infection. - Environmental factors, such as contamination from neighboring facilities and surface water, also contribute to the spread of S. Dublin. **Diagnosis and Treatment:** - Bacteriological culture and polymerase chain reaction (PCR) are used to detect S. Dublin. - Treatment focuses on supportive