Relation between Eisen foetida and sickness in vertebrates

[Nat1]

http://www.sciencedirect.com/.../article/pii/S1532045600002131
I find this very interesting, as I've been feeding E. foetida to salamanders, getting mixed results. I will share my experiences, and then my hypothoses. First I fed unrinsed E. foetida to my A. mavortium, who became sick and died a month later, but I also fed him Tenebrio molito, which I didn't realize, could also have been what killed him. Then I fed unrinsed E. foetida to A. mexicanicum, who eagerly took, but later developed long-term sickness, and refused to touch them. Next, I began letting them soak for 20 minutes in warm water before feeding them to S. algira adults and juveniles, T. marmoratus adults while on land, N. crocatus juveniles and Cynops ensicauda adults. The S. algira adults got slightly and the T. marmoratus adults got seriously sick, and were not the least bit eager for them the 2nd time as they were the 1st. I never cut any of these worms, but gave the according to the size of the animal. The S. algira juveniles, N. crocatus juveniles took very small E. foetida which had developed coloration, and would take them meal after meal. The Cynops ensicauda adults took medium sized E. foetida repeatedly - do they perhaps have an immunity to E. foetida's coelomic fluid? Soaking in warm water first seems to remove some of the slimey excretions(perhaps making them slightly less dangerous, but I would by no means say safe), but a scalded, dead worm is of little interest to me or my animals. From my trial and error (this wasn't an animal experiment), it appears that E. foetida develops toxicicity with maturity. I don't know of any studies to suggest that other of the Eisenia genus such as hortensis have this toxic coelomic fluid.

[Nat1]

Since I initially posted this, I tried feeding adult, unwashed E. foetida to the same T. marmoratus during aquatic period. The same animals which got sick before from them on land, greedily gorged on them in water for several months! The water and the filter which was running may have played a role. My A. mexicanum had no filter. One last note is that I take my worms from a bucket where there is sometimes rotting food. I have read for snails, that before you feed them to anything, it is best to feed them cornmeal which cleans their gut from any garbage they may have eaten.