Hi Emily

Several sources list the half life of Praziquantel at 0.8 to 1.5 hours with elimination form the body in 24 hours.

http://www.bayer.ca/files/BILTRICIDE-PM-ENG-30NOV2007-116425-2.pdf
http://dailymed.nlm.nih.gov/dailymed/archives/fdaDrugInfo.cfm?archiveid=4631
http://en.wikipedia.org/wiki/Praziquantel

For horses with an unknown deworming history and posssible very high burden, general recommendation is to start with invermectin, three doses total, given over two week intervals.

More info in the fILES

 Deworming     tinyurl.com/ygyhr6c

Nancy C in NH
ECIR Moderator 2003

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