E-Cunciculi

Question
Can you please advise whether e-cuniculi is contagious. I have read conflicting reports which state that once it has left the kidneys it is not yet others say there may be recurrences of contagious periods.  I am interested in taking on another rescue rabbit but know that it is highly likely that it has it although I dont believe a blood test has been done.  I do not want to risk the health of my other rabbits that it would be in contact with (bonding issues aside of course) if there is any chance they could catch it.  The rabbit concerned is 6 years old and has been on its own and therefore can only presume it caught it from its mother.  Further, does treatment with fend*****ole (cant remember exact name)(which it is receiving) actually kills the parasite or just control it.  Thanks

Answer
Dear B.J.,

I, too, have heard conflicting reports, but the consensus I've heard from vets and other people with experience in parasitology have told me that the parasite is reproductive and contagious only for approximately two weeks after initial infection of the host.  After that point, it stops shedding spores and is no longer contagious.

The treatment most often used for E. cuniculi these days is fenbendazole (Panacur), since it's the only one of the benzamidazole drugs that has a clinical study backing up its efficacy:

www.bio.miami.edu/hare/fenbendazole.pdf

According to the study, the drug does *kill* the parasites.  There are other very promising drugs now being tried, including pyrimethamine (the protocol for this treatment can be found at www.medirabbit.com under "parasitic diseases"; if you can't find it, let me know and I'll find the exact URL for you).  Another is ponazuril (brand name Marquis, made by Bayer) which was developed to treat an E. cuniculi-like parasite in horses, but shows great promise in killing E. cuniculi in rabbits.  I have used the drug to treat coccidia in my sanctuary jackrabbits (coccidia are closely related to E. cuniculi) and have had pretty spectacular results.  The only problem is that the drug is ridiculously expensive:  one horse tube costs $150.  But if you have a vet who can buy a tube and use it for other patients, you might want to ask about that.

Blood titers really don't tell you much about the state of E. cuniculi infection.  Rather, they tell you only if the bunny has ever been exposed.  A paired titer *might* give you a clue that there's an active infection, but you can never really be sure.  That's why we just treat for it and don't bother with blood titers.

If this were my bunny, I would not be very concerned about him transmitting E. cuniculi to other rabbits, if his husbandry is good and he's not in contact with his own urine (from which he could be reinfected constantly, hence never ending the infective cycle).  And with the advent of all these new drugs, I think it's worth giving him a chance at having a bunny pal.  :)

Hope that helps!  I'm very sorry for the delay in answering.  We had an emergency bunny surgery the day you wrote, and things have been crazy ever since.  Hope the delay didn't cause any problems.

Please write back if you have any other questions.

Dana