See if he'll let you take home a tube of Banamine paste for right after foaling, so you can give her a dose is she seems uncomfortable. Or, perhaps he'd be willing closer to that time to let you take home just one dose of the injectable that you can give orally (it's really icky tasting, but will still do the job, just a bit slower; it's an off label use, so he might not be willing). [it's given just like the paste wormer.]