We've a got a goat here who had a bad chest infection - prescribed 2.5 ml of Alamycin (5 days) and anti-inflammatory injections (3 days).
She then developed mastitis after a difficult kidding a few days later, vet said to repeat Alamycin and other thing at the same dose for the same amount of time.
She wasn't eating and not strong, lost the kids.
This is done, she is still being stripped daily. Not long back on her feet and starting to eat etc. Hates udder cream and massage (this is how we know she's feeling better - by how much she can give me the run around!)
So different circumstances, but if it helps...
I've read that goats need a longer time on antibiotics etc as they absorb drugs differently than other animals. ANd of course, not much is approved for goats..