SMZ's are an antibiotic...I always make sure to have this stocked. Great stuff. Here you can only get it from the vet or online with a prescription.
Here is a link just to give you an idea of what it is. It is not that exspensive if you can get the vet to let you kust pick some up...this...
Oh & if she is bad with shots this trick always works. I had a colt who was got very sick at 3 weeks old & had to get antibiotic shots twice per day....I had to give the shots myself in his neck & he hated it. You had mentioned your mare likes her neck scratched.....if you just keep scratching...
Just some things to think about...
These horses are definitely not one month projects. You have to do a minimum 30 days of quaratine if not more. Quarantine can be very tricky if you have visitors to your farm or animals, espically from your other post you have mentioned that you have a...