Salmonella Kills at Least 22 horses in Outbreak in Iceland
An outbreak of salmonellosis has killed at least 22 horses in Kjalarnes, Iceland. A total of 41 horses were infected. This is a very high mortality rate (>50%) for what I assume is a group of otherwise healthy horses, as compared to the more compromised populations which are usually present in equine hospital outbreaks. It is unclear whether the high mortality rate may be due to a particularly nasty (virulent) strain of Salmonella or the unavailability of aggressive supportive medical care which is needed in severe cases of diarrhea in horses.
The source of infection was thought to have been a sedimentation pond in the horses' pasture. The article contained no information about potential sources of contamination of the pond, or about the the strain of Salmonella involved.
- Outbreaks of salmonellosis are uncommon on farms, but they can occur.
- Mortality rates with salmonellosis can be high, especially without (but sometimes even in spite of) aggressive (and expensive) medical care.
- Prompt investigation is critical to identify the source(s) of infection and try to prevent further exposure and additional cases.
- Good routine infection control measures should be in place to reduce the risk of entry of Salmonella onto a farm, as well as transmission of Salmonella between horses (and between horses and humans) if it makes in onto a farm.
