revolution and E cuniculi

Question
Hi Dana,
I have a rab with e.c. Panacur isn't keeping up with it anymore. I read that revolution can help disturb the parasite's reproduction but also think I saw a caution from you regarding using revolution on a rab with e.c. because of a breach to the blood-brain barrier.This rabbit has mobility issues now, if that tells you anything about where she is with the parasite. The vet didn't find any information as to its safety or effectiveness. Do you know if it's safe to try? Thanks Shannon

Answer
Dear Shannon,

I have not (yet) heard of Revolution (selamectin) being effective against E. cuniculi.  It is a GABA agonist, which means that it interferes with the normal function of a neurotransmitter (GABA) in some species, notably nematodes and some arthropods.   Since the protist parasite E. cuniculi doesn't have a nervous system, let alone neurotransmitters, it would certainly not work the same way against them as it does in multicellular animals.  There may be some other mode of action, but I am not aware of it.

I do know that E. cuniculi can also be treated with Ponazuril (toltrazuril sulfate), which you can buy as Baycox.  

I would be very cautious about giving a bunny with known E. cuniculi infection any type of drug such as ivermectin or selamectin.

Hope this helps.

Dana