What is Salmonellosis? 

Salmonellosis is contagious and zoonotic bacterial infection caused by Salmonella spp, which causes enterocolitis. Clinically normal horses can transiently shed Salmonella, with shedding more common during: 

  • Concurrent illness: antibacterial usage, physiological disturbance
  • Stress: transportation, social, nutritional 
  • Gastrointestinal disturbance: motility (especially colic), feed change

Clinical Signs: Clinical signs of salmonellosis include the following: 

  • Diarrhea (soft feces to projectile, watery diarrhea) is most common, however, horses may have normal feces
  • Fever (patient may have normal temperature, especially if treated with NSAIDs) 
  • Lethargy
  • Anorexia
  • Colic
  • Localized infection (e.g. joint or bone infection)
  • Sepsis/septic shock • Laminitis is a common sequel to enterocolitis
  • Abortion with infection by Salmonella serovar abortus-equi (does not occur in the United States of America)

 Foals are commonly more seriously affected when compared to older horses, with profound systemic illness including:

  • Hemorrhagic diarrhea 
  • Pneumonia 
  • Meningitis 
  • Inflammation of Growth Plate 
  • Septic arthritis

Diagnosis: Diagnosis of salmonellosis is made by a veterinarian by fecal culture, PCR testing or sample submission. 

Treatment: Treatment of the severe form of salmonellosis is based on IV fluid and electrolyte replacement and efforts to control the host’s responses initiated by the systemic inflammatory response.

Prevention: Prevention of salmonellosis is difficult, because the organism is present in the environment as well as in the feces of some healthy animals. Isolation and increased biosecurity are needed to prevent spread of the disease.


February 24, 2024
MRC Marguerite-D'Youville, Montérégie, QC
Confirmed Case(s) - Voluntary Quarantine
November 10, 2023
Frederick County, MD
Confirmed Case(s) - Voluntary Quarantine
October 14, 2023
MRC Brome-Missisquoi, QC
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