Endurance.Net Ridecamp Archives

Hello All,
Looking for some advice from everyone.  I am thinking about doing the SafeGuard 5 day double dose worming.  I have 7 horses and when I did the math (if I did it correctly) it come to about $250.00 to do them all.  I was wondering if anyone has any suggestions/advice as to something more cost effective that will deliver the same results?? Also one of the 7 is an older (22) mare that may be pregnant.  She was a rescue last Sept. and I did have her palpated the week she came here.  Vet said she was open but she is sure looking preg. to me now (since vet assured me in Sept. that she was open, I am now taking the wait and see approach but have given recommended shots--just in case!!).  Rumor was that she was bred to foal late March or early April.   I sure don't want to do anything to hurt her.  Would something like this be recommended given her age and poss. pregnancy??  I have been worming with Ivermectin every other month (including the older mare since she came here) but have never done a 5 day double dose tx.  I understand (please correct me if I am wrong) that this is the only thing that will get the small encrusted Strongoyles (sp) larva??  Any suggestions or advice???  
Thanks to all,
Jan