Unlimited access >


Two months ago a new horse arrived at the boarding barn, fully vaccinated and in excellent health. No other horses have arrived or left the property since his arrival.
A week ago he presented with lethargy and spiked a temp with some mild swelling under jaw. Vet called immediately and drained some pussy fluid. Thought perhaps an infected tick bite and put on Doxy.
The preliminary results of the culture came in late Friday, indicating this is Strangles.
He and his 2 pasture buddies are now isolated and all precautions are being taken.
I am taking my guys temperature daily and they have had never any direct contact with him since his arrival.
Is it possible he has been carrying this around with him all this time?
Has anyone heard of Strangles showing up like this out of the blue?

1 Like

Some horses are carriers of the bacteria, so it’s possible this one was, or that one of the pasture mates is a carrier and passed it to him.


The horse has been here for 2 months. Perfectly healthy.
Would it take this long for it to show up?
His 2 Pasture mates have been together for quite a while. So far, they’re fine.

My thoughts: 2 months would be an unusually long time for the new horse to have been incubating strangles. Incubation period is typically 2 weeks or less. The new horse has likely been kept separate for 2-4 weeks before mingling with pasture mates. I suggest that one or both pasture mates are carriers who have infected the new horse.


It’s very contagious and can survive in the environment and in water troughs etc for weeks. While one of the pasture mates being a carrier is most likely, it also could have been passed along by someone who handled an infected horse on another property then came to yours, by using a water trough on a trail ride, by close proximity to other horses on trail rides etc.

I believe one of the vaccine options that were available several years ago was shown to occasionally cause a mild clinical case but not sure if that’s still available (hopefully not!).


My then-horse developed strangles years ago out of nowhere. He hadn’t left the premises for many months. His was the sole case among about 20 horses. This was a show barn and we quarantined. Boarders were SO irritated at me and I took it hard. To this day I wonder why he, and only he, came down with strangles, or whether he was misdiagnosed. I don’t recall whether the vet cultured a sample.


Over a few years we had several horses on the farm end up with abscesses (but no other symptoms) after vaccinating young horses with the IN vaccine. Sometimes it was a horse that had just been vaccinated, sometimes it was a pasturemate or horse in a neighboring field. However they always cultured positive for strep but not the strain that causes strangles. It was super weird and we stopped using the vaccine.

1 Like

When you use the IN you have to give it absolutely last, after everything else has been done and packed away. It spreads widely in the air and survives for a long time so it gets on syringes, other vaccine bottles the vets gloves etc and can be subsequently injected into the same horse or another horse alongside another vaccine. My vet rarely gives it but when she does we walk the horse out to the parking area to do so.

What happened at your barn is pretty well understood by the vet community, or should be!


Yes the vet always gave it last-- some of the horses that got abscesses were ones that the vet did not vaccinate or treat and that were out in their fields at the time. There was no direct exposure.

1 Like

Ugh, it’s so persistent. That’s why we don’t use it anymore, too many similar stories.

Yes…our Vets are knowledgeable and are as equally perplexed as the rest of us. Two months is a very long time with no symptoms.

We’re hoping that either the preliminary tests are wrong or that this is a one-off and no others contract it.

The two paddock mates have been at the barn / turned out together for at least a year and, so far, have zero symptoms. If one or both are asymptomatic carriers you’d think other horses who lesson / trailer with them would have come down with strangles by now.

Could a farrier have brought it on them? That once happened at a barn I boarded at in Florida…or at least our best guess. None of the horses had left the barn in over a year and no new horses had been brought on property. The only thing the vet could figure was the farrier the lady used at the time was also the farrier for a local farm that had had an outbreak. While he had sanitized all his tools and trailer after he found out he had visited and trimmed this horse prior to being made aware by the other barn. Just a thought :woman_shrugging:.


Horses can shed the bacteria for months after an infection, even asymptomatic (carrier), which can be up to 40% of infected animals. The bacteria can also survive for about 3 days outside of a host in dry conditions, 4-6 weeks in moist conditions.

Since his pasture mates are fine thus far, I’d bet one of his pasture mates is a carrier and the stress of moving lead to an infection. They can harbor the bacteria for literal years in the respiratory system, without it being a problem.

Make sure all of your equipment is sanitized even if it’s not shared, bleach your boots coming in and out of the facility, no matter how close you are to infected horses. Good on taking temps daily. Avoid other horses other than your own, and do not travel to any other equine facility. Just batten the hatches and hunker down. It could be a while before the infection is totally clear. Make sure your farrier and vet are aware if you use different healthcare personnel too.


Strep equi equi does live in soil. There was a farm locally in my last home town that would have a strangles case every few years unrelated to horse movement; vets thought it was just endemic to that farm’s ecology.


I have, yes. Last year a friend got some horses from a feed lot. She kept them separated from her original herd for two months and then a month after mixing the new horses in with the old, two of the old horses developed strangles. None of the feed lot horses ever showed any symptoms, but the vet said it’s possible that one is an asymptomatic carrier. My friend also had a new farrier in at some point, so there’s a possibility that the farrier was the vector and not any of the feed lot horses.

The absolute worst part about this is that the one horse started showing symptoms of strangles at the end of January and now, almost ten months later, he’s still sick and his strain of strangles appears to be resistant and just never ending (I know she’s at least talked to specialists, but otherwise I know very few of the details about his care). The other horse that got sick recovered within a couple of weeks and has been fine since and none of the others ever showed any symptoms or illness.


My daughters horse was a carrier. We bought her and kept her by herself and when we finally introduced her to my other 2 horses they both got strangles while she happily stayed 1000% healthy.

My 2 had zero contact with any other horses and no contact with farrier or vet for over 4 weeks before.

1 Like