Equine perinatal disease due to Salmonella anatum.

This study explores a rare case where an equine disease was found to be caused by Salmonella anatum, an organism typically associated with cattle, in a week-old foal and its healthy-looking dam.

Introduction

• The study begins by explaining that Salmonella anatum (S. anatum), analyzed at the Salmonella Reference Laboratory, is usually observed in non-human sources, primarily in cattle, feedstuffs, and abattoir swabs.
• However, it also notes the past reports of S. anatum associated with equine disease. Specifically, Morse et al. (1976) observed S. anatum causing enteric disease in adult horses in the United States, while Kumar and Gupta (1972) found the organism in an aborted foal in the United Kingdom.

Case Details

• The current research revolves around a case where a one week old foal demonstrated a significantly swollen hock.
• A week later, on examination, synovial fluid, tainted with flecks of pus, was withdrawn from the foal’s hock and S. anatum was identified in the fluid sample.
• Moreover, one month later, the same organism was also found in rectal and cervical samples taken from the dam, despite the dam showing no symptoms or signs of illness.

Possible Source of Infection

• The researchers suggest that the watering point, which was used by horses, numerous cattle, and native fauna, could be the most probable source of S. anatum infection in the desert environment where the incident took place.
• This conjecture is strengthened by the fact that a cattle station nearby was also drawing its domestic water supply from the same source, coinciding with an occurrence of undiagnosed diarrhoea among personnel working at the cattle station.

Lab Analysis

• The Salmonella strains isolated from the cases were sent for typing to the World Health Organization’s Salmonella Reference Laboratory at the Institute of Medical and Veterinary Science in Adelaide.