Neutropenia and salmonellosis in hospitalized horses.

The study investigates the relation of neutropenia (low white blood cell count) and salmonellosis (infection with Salmonella bacteria) in horses hospitalized at the University of Missouri Veterinary Teaching Hospital within a year. The researchers identified common symptoms and established the value of hematologic (blood) monitoring in horses to prevent colitis (inflammation of the colon).

Investigation and Findings

• Researchers diagnosed colitis caused by salmonella in 9 horses that had been hospitalized for various reasons. They identified common symptoms, including diarrhea, fever, and a low count of neutrophils (a type of white blood cell), or a rapid decline of neutrophil numbers.
• The study emphasizes the importance of hematologic surveillance (monitoring blood parameters) in hospitalized horses. Evidence of this was demonstrated in a separate group of 9 horses that were spotted with neutropenia early and treated promptly before they could develop colitis.

The Role of Bacteriologic Culturing

• Researchers carried out bacteriologic culturing of fecal samples in 28 clinically normal horses. The culturing came back with only 2 salmonella isolations, both S. Manhattan, indicating that this type of salmonella was not common among these horses.
• Salmonellae isolated from horses diagnosed with colitis were all S. Typhimurium, and they displayed similar antibiotic resistance patterns, suggesting a common source of infection with this bacterial strain.

Implications of the Study

• This study underscores the correlation between salmonellosis and a decrease in neutrophil count in horses, signaling potentially critical health issues.
• It highlights the significance of routine hematologic surveillance in the early detection and prompt treatment of neutropenia, thus possibly averting the onset of colitis in under surveillance horses.