Among adult horses, which statement accurately reflects Salmonella infection?

• A. It is never nosocomial
• B. It is one of the most diagnosed infectious diarrheas in adult horses
• C. It never causes subclinical carriage
• D. It is always fatal

Answer: (B)

Salmonella in adult horses is a common cause of infectious diarrhea, and its impact goes beyond just the sick animals. It is frequently diagnosed in horses with diarrhea and is well known for causing hospital- or yard-based outbreaks because the organism can persist in the environment and spread via contaminated bedding, water troughs, equipment, and even personnel. A key point in its epidemiology is that many horses can shed Salmonella without obvious signs of illness, so subclinical carriage is a real and important part of how the infection behaves in populations. Mortality from Salmonella varies and is not inevitable, with outcomes ranging from recovery to severe illness, depending on virulence, strain, and how quickly treatment is started. Because of these characteristics—frequent recognition in diarrheal cases, potential for nosocomial spread, and the existence of asymptomatic carriers—the statement that it is one of the most diagnosed infectious diarrheas in adult horses best reflects the reality of Salmonella infection in this species.