It would be advisable to ask your vet about it. It has several uses, one of which is to hold PG's, but also to bring a mare in and perhaps others? The other responses are correct, it is expensive and it can effect a womans cycle. The dosage so far as I know is 1 cc per 100lb, but that is when I used it for the purpose I used it for. There is a specific way to start the dosage for them and also take them off of it depending on what you are using it for.
Good luck!
Beth