The prevalence and epizootiology of salmonellosis among groups of horses in south east Queensland.

This three-year research studied the incidence and distribution of salmonella among groups of horses in southeast Queensland, Australia. It was found that 23.81% of horses had one or more instances of salmonella, with S. anatum being the predominant type identified.

Methodology and Findings

• The research was conducted at the University of Queensland’s equine clinic, where fecal samples from 462 horses were collected and tested over the span of three years.
• In total, 1178 samples were taken and cultured, with 185 of them testing positive for salmonella, resulting in the identification of 21 different serotypes of the bacteria.
• The most prevalent serotype found was S. anatum (54%), followed by S. ohio (11.27%) and S. typhimurium (9.4%).
• Among the tested horses, 110 (23.81%) tested positive for salmonella at least once. Forty-two of these horses (9.09%) tested positive more than once.
• The primary bacteria found in the main drains of the stables was S. anatum, with 71.43% of all positive samples coming from this location.

Prevalence in South East Queensland

• The researchers expanded their investigation to a larger population of horses in South East Queensland outside of the equine clinic.
• In this non-clinic population, the prevalence rate of salmonella excretion was quite lower, at 1.65%.

Salmonellosis in Hospitalised Animals

• Throughout the research period, no acute cases of salmonellosis (a symptomatic infection caused by Salmonella bacteria) were reported among the hospitalised animals.
• However, the research team found that Salmonella contributed to six cases of chronic diarrhea. S. anatum was present in all these instances. The most severe case involved both S. anatum and S. typhimurium, discovered at multiple locations in three autopsies.