Can we talk about Salmonella?

A “virus” went through our barn last year at this time – symptoms were fever, not eating/drinking, and some horses did display mild colic symptoms – there was no diarrhea and no coughing or respiratory symptoms. 5 of the 6 horses at the barn got sick but recovered after about a week.

Now here we are again, same time of year and it’s like deja vu. One of the horses got sick with the same symptoms and after much discussion, owner and vet decided to run the test for Salmonella. Horse comes back very low positive (I’m told if the test was 3 points different it would’ve been a negative). A second horse in the barn (his neighbor) falls ill with the same symptoms and sadly had to be put down with complications from his illness. He was not tested for Salmonella but assumed to have the same.

We’re all waiting and hoping and praying this doesn’t continue to spread to the other horses in the barn now. BO is working with our vets and doing everything possible to isolate the sick areas and limit any spread of illness to other horses.

Our vets have been very honest with us in letting us know that they don’t know of any other farms that have dealt with Salmonella and are at a bit of a loss here, having only seen Salmonella cases in the vet hospitals during their vet school days. They are researching and working to find answers for us and ways to move forward.

My BO (bless her!) as well as all of us boarders are so devastated and concerned about how we move forward. Vets have discussed the desire to test all of the horses in the barn once we get past this a bit to see if one of our horses is a carrier and is shedding the bacteria. A few of the horses do come and go from the farm for trail rides/clinics/etc but based on the timing and nature of the outings in conjunction with the timeline of the illnesses, we feel that the illness is actually originating from within our own barn and perhaps the stress from the trips is just making the horses more susceptible. It’s a small farm so although BO does have the ability to separate horses from each other, all of the pastures have potentially been “contaminated” at this point, especially assuming last year’s “virus” was also a Salmonella outbreak.

We’re at a loss though – how is this happening? BO runs a clean barn and is a responsible horsewoman. I understand that Salmonella is just “out there” in the environment and that horses are probably exposed to it all the time. I grew up at a very large boarding/lesson/show barn that had literally hundreds if not thousands of horses passing through there during the 20ish years I was there. We trailered to other farms to show. I’ve kept my horse at the state fairgrounds countless times in stall where strange & no doubt, stressed horses have stayed… We’ve NEVER experienced anything like this or heard of anyone else experiencing this. We don’t know what this means for us moving forward – for our own barn activities and in our future interactions with the area horse community.

I thought I’d come to the COTH community to see if others have been through this before and could share their experiences. Where do we go from here?

Some horses are carriers for the bacteria and when stressed, shed the bacteria. We also always tested horses in the hospital for 3 days in a row before one was considered “positive”. They never went off just one swab.

Thanks bugsy – yes it was my understanding that several samples were taken from the sick horse to help determine whether the salmonella was present. I think the vets’ intent is to do the same for the remaining horses in the barn to help get an accurate answer.

I don’t know that much about it, but thought that horses pretty much always presented with at least moderate diarrhea and that fatalities were typically caused by that. Do you know if they tested for anything else, like Coronavirus? Is it possible the salmonella was coincidental? I do know that it can be very hard to eradicate once it’s been present on the grounds-- New Bolton had a huge issue with it a few years ago.

Highflyer - that was my impression too and a lot of the articles I’m finding online seem to point to diarrhea being more prevalent with Salmonella. That’s why it was a bit surprising to hear that this was our possible diagnosis and that the 1 horse tested for it.

I read up on Coronavirus just now after seeing your post. It does sound more like the initial symptoms our horses had. And the 1st horse who got sick only showed those symptoms at first and for about a week. He started to get better and then went downhill again…he got colicky with several hours of diarrhea that day (the only one to really have it!), and then that’s when they decided to do the test for salmonella. I could totally see where the salmonella was just conveniently able to gain a foothold on him due to the fever, lots of banamine, aggravated ulcers, etc he had from the initial sickness and drag him back downhill again. I’ll ask to see if anything like this was considered during all of the vet visits – I don’t know for sure what all was ruled out during the many barn aisleway conversations :frowning:

What’s the climate like this time of year? Does it generally get warmer and wetter, or are you still usually a frozen tundra?

Is it the same horses who got sick last year? Totally different? An overlap?

Any change in forage? Turnout?

Both Coronavirus and Salmonella should cause notable diarrhea if the horse is symptomatic, which I would consider them to be if running a fever. It is not uncommon for horses to shed Salmonella. CSU was going to run a study on exactly how prevalent shedding is in unsymptomatic horses and whether or not history of being symptomatic of the disease is needed or not. I don’t think they have gotten funding for that. I only know about it because they sent me a questionnaire last year to gauge interest in past clients sending in manure samples regularly for the study.

What you describe sounds more like what a friend’s horse had in my barn in December. He had some gastric reflux and enteritis as his colic symptoms. Primary issue was going off feed and the high fever. He spent 5 days at the clinic being tested and re-tested for any virus or bacteria they could think of and found nothing. Eventually, it resolved.

Based on your description, I don’t think Salmonella is the likely answer. I think I’d do a broader panel of testing for viruses/bacteria, check liver and kidney levels, abdominal ultrasound when showing colic symptoms…

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We’re in the mid-Atlantic so very mild winters – rarely frozen. So far, the two horses who got sick this year were among the ones sick last year. The sickness started with a different horse this year though, who was on opposite sides of the barn and not not turned out together with last year’s 1st sick horse. The 2 sick horses this year are stall mates and share a fence but not turned out together. No real changes in turnout or forage – hay quality changes from load to load of course and hasn’t been as good as last year’s hay but the hay source hasn’t changed.

And I just learned the vets tested for about 5 things - Salmonella and Coronavirus were 2 of 5 but salmonella was the only thing that showed positive.

IPEsq - Interesting that you agree that the diarrhea should be a biggie for both of those. Seems like we’re dealing with more than one issue here and the salmonella is just a secondary issue to whatever the initial virus is.