Diarrhea: Why Culture?
Diarrhea is a potentially life-threatening condition in horses. It's also frustrating from a diagnostic standpoint because, even with the most complete/comprehensive testing, a cause is only identified in a minority of cases. This is true for other species too, including people, and is a reflection of the complex nature of the intestinal tract and the numerous possible causes of intestinal disease. Diagnostic testing obviously costs money, so if it gives us an answer less than half the time anyway, it begs the question - why bother? Well, here are some points to consider:
- In some situations, you may find a cause that requires a different treatment, so diagnosis has a direct impact on patient care and probably the outcome.
- Many causes of diarrhea are infectious and it's important to know if other horses may have been exposed to a transmissible pathogen.
- Some causes of diarrhea, especially Salmonella, can also infect people, and it's important to know to what people have been exposed.
- It's also important to know whether a horse might still be shedding a transmissible pathogen after its diarrhea resolves. For example, horses with salmonellosis can shed Salmonella for a while (often a few weeks, sometimes longer) after they have recovered from their diarrhea. This could be a source of infection for other horses and people.
- Outbreaks of diarrhea can occur. It's much better to know early on what you are dealing with, rather than waiting until mulitple horses have been infected.
I consider diagnostic testing money well spent in cases of diarrhea. Some people don't want to test because they don't want to know, particularly about Salmonella. However, it's been proven again and again that the "head-in-the-sand" approach will backfire when it comes to infectious diseases.
