Horse has multiple (moving) edema (swelling)...

There is a mare at our barn who has had multiple location, swellings that are ongoing without explanation. Vets have pulled blood and given antibiotics-nothing has helped. Her elbows have swollen, just like a shoe boil, but she now has edema down her midline. Has anyone ever had this type of thing happen?? It all started with (what we thought) was a spider bite and a swelling on her side, behind the shoulder.

Is she turned out full time? Stalled at all? How long ago was the bite/initial injury? How are her vitals (edited in reference to the post below)?

isn’t swelling down the midline a symptom of pigeon fever? (but wouldn’t the bloods have shown that?)

How weird. I know some stalled horses get this sort of thing, but not sure what causes it. If she is stalled, is she on concrete? Would explain the elbows.

If she’s not out 24/7, try that for a couple of days and see if they disappear, and keep up with the vet. Does she seem well in herself?

Does she have a fever? A similar thing happened to my mare last year, but it was accompanied by a high fever. We never found the cause: vet had thought it was a virus, but testing later showed it was not.

Owner may want to consider having her lungs ultra sounded to make sure the fluid isn’t there as well.

isn’t swelling down the midline a symptom of pigeon fever? (but wouldn’t the bloods have shown that?)[/QUOTE]

That was my first thought as well (being in a pigeon fever area).

I do not believe PF is diagnosed through blood work…

Diagnosis of pigeon fever abscesses is often made based upon swellings in specific areas of the body and the presence of characteristic thick green-tan purulent exudate. Culture of the discharge will confirm nitrate positive Corynebacterium pseudotuberculosis. Use of serology for the diagnosis of external abscesses is unreliable, as some horses do not mount an antibody response to external infection. The typical progression of an external abscess will involve soft tissue inflammation and edema surrounding the lymph node. This stage may be accompanied by a significant amount of discomfort as the swelling becomes firm as it enlarges. About a quarter of infected horses will develop fevers up to
104?F. The abscess generally matures, resulting in hair loss and rupture of the skin allowing the abscess to drain; however, many times veterinarians will be asked to intervene and open the abscess prior to full maturation

OP - have the vets “tapped” the swellings at all to see what type of fluid they contain? I have heard of low level PF infections, where the horse has swelling that does not quickly progress to a burst abscess - no fever etc either.