Praziquantal persistence in manure and soil

[JCAS]

I free range my laying flock among my livestock. Therefore I manage intestinal parasites through management practices (pasture rotation, not-overcrowding, cleanliness, cucurbit seeds in case they are actually effective) so as to not expose my hens, and thus their eggs and me, to anthemintic residues excreted in manure. My sheep may have been exposed to tapeworm and I need to decide if I should treat them, using Praziquantal. I have found everything I need to know about to protect my hens, eggs, and myself from contamination should I go that route (excreted from the treated animals within 24 hours via urine and manure, withrawal period for eggs is 17 days should the hens consume the drug in manure). What I can't find is information about the persistence/half life of Praziquantal in animal manure and soil. Is there anybody out there who has discovered this bit of information?

 

[centrarchid]

My state will not let me use the stuff in aquaculture setting in part because of persistence issues. I have to flush systems to get rid of it.

 

[Eggcessive]

Why not have some of your sheep’s droppings checked for different worms and larvae? Have you seen tapeworm segments in their droppings? I would think if they had a worm load that you would want to treat whatever type they had, no matter if some meds ended up in the soil. It would probably be minute.

 

[JCAS]

Thank you for the input about prazinquantal being banned in Missouri. After I left my initial post I was able to find the following:
https://www.ncbi.nlm.nih.gov/pubmed/22910218This is the first university study I have found supporting the use of cucurbit seeds as an anthelmintic, and specifically for tapeworm, so I will add my quadrupeds to the monthly squash seed feedings.
I have found studies showing Ivermectin persists for a period of time in compost, so I would presume that other oral worming medications would do the same.