Re Goats - Please make sure you are not given Tilmicosin - which is Mycotil (spelling) - and fatal to goats, though ok for sheep. Just in case you find the Alamycin is not doing the trick and need to swap to different AB's. Engemycin and Alamycin LA is good though, you may have to repeat the Alamycin more often for the goats than for sheep, different rates of metabolism.
Fingers crossed it works.
Have you brought any other sheep/goats onto your farm in the last year? If no, then the ram may well have introduced it... is he affected as well? If yes, definitely speak to the breeder.