Does anyone have any experience of this in horses? Not one of mine, but my YO's mare. She's obviously under veterinary care, but I am obviously concerned for the horse and also for mine.....
Crikey, a good one to keep looking at. Sorry i have never come across it. I do hope its not too serious and the horse gets better soon - doesn't spread.
Usually this is caused by Strep zooepidemicus which isnt contagious or beta haemolytic strep which is a normal commensal of horse's skin. Its not that common in horses, but can occur in immunosuppressed horses, those that are "over" fit and those that have had recent stresses, eg racing, anaesthesia or shipping.
Diagnosis is by transtracheal wash or bronchoalveolar lavage usually ( with culture of aspirates) and/or ultrasound.
Treatment would usually be gentamycin or penicillin or metronidazoles if anaerobic bacteria are found in the aspirates.
If it was viral Id be much more worried, but bacterial infections usually need a "way in", so unless your horeses have been sick of late, Id try not to lose a night's sleep over it!