E-cuniculi & Ponazuril

Question
QUESTION: Hi Dana,

Just wanted to check back with you, to see if you still feel positive about treating ecuniculi-infected bunnies with Ponazuril.  You recommended it to me a year or two ago, but at that time, not much was available in the way of studies.

Our little guy is coming up on approximately 7 years old this winter and has previously tested high positive for e-cuniculi.  He's got hind leg weakness that comes and goes, but it's mostly on, at the moment.  He's had about 6 or 7 rounds of Panacur over the last couple of years, with good success, for the most part, but his last round, this past August, didn't really improve his floppy back legs at all (strangely enough, we did see some improvement with his nasal problems, though - it definitely lessened his sneezing and nasal discharge).

Nonetheless, despite all of his problems (he also has kidney stones...sigh), he still seems happy and gets around just fine.  He still even jumps up on my chest & stomach, if I'm laying down in the floor and have one of his favorite treats, like grapes or apples!  He just has a lot of weakness in his back legs that varies in intensity.  Usually, a round of Panacur strengthens them and it will last for a few months, but this last time, we just didn't see any improvement, so we were thinking about trying Ponazuril.  I believe you have said many time, Panacur and Ponazuril are really the only two drugs deemed both safe and possibly effective for e-cuniculi, therefore, I just wanted to check back and see if you were still feeling good about it.  The only medicine he is currently on is Baytril, which he's on long-term, having been on it consistently since the first of this year, and even back into previous years.

Anyway, I really hate watching our little guy struggle at times, if something could make him better, but on the other hand, I don't want to over-medicate him or cause him additional problems by introducing a new drug.

Just let me know what you think, as I believe you've treated many a rabbit with Ponazuril yourself and can probably attest to any safety concerns, side effects and effectiveness.

As always, thanks for your great advice!

Paul

ANSWER: Dear Paul,

Your little guy is lucky to have such an attentive, caring family!

I can certainly attest to Ponazuril's safety, though I can't guarantee that it will help him any more than the Panacur does with the E. cuniculi.  There's some indication that Panacur merely "suppresses" the parasites, but may not kill them.  If that's the case, then inflammation can still cause problems, and the parasites can cause damage when the drug isn't being administered.

Ponazuril is *killer* against coccidia, though.  If your vet is hesitant to invest in a tube (not cheap!), then you might mention that.  It kills the coccidia in 2-3 doses (though we give 5, to be sure), which is a far cry from endless dosing with potentiated sulfas that don't really work.  Your vet could use the rest of the tube for coccidiosis treatment, if s/he doesn't dispense the whole thing to you.

I would not hesitate to give the ponazuril a try, if safety is your only concern. But it's expensive, and you need to dilute it to a concentration and consistency that you can easily administer to a rabbit (it comes as a very thick paste for horses).

If you/your vet need instructions for dilution and dosing, then please let me know.

Hope this helps.

Dana

---------- FOLLOW-UP ----------

QUESTION: As always, thanks for all the good information!  Have a few follow-up questions for you:

Have you noticed one drug being more effective than the other, when it comes to treating e-cuniculi or is that too hard to say?  (that is Panacur vs. Ponazuril)

I suppose if I meet any resistance or reluctance on the part of our vet to prescribe Ponazuril, then I suppose I could simply buy some myself, off of the internet, and then administer it accordingly.  Does it come flavored in some fashion, like the Panacur?  Luckily, our little guy loves the taste of Panacur and will happily lick up a daily dose from a large spoon, but obviously, I don't know anything about the Ponazuril.

You mention damage that could be ongoing when Panacur is not being administered.  Is there some sort of limit to how often he can take it?  Right now, he typically will go about 3-4 months in between 30-day rounds of the Panacur, but I'm wondering if we could give it to him more frequently, like every other month, if there isn't any long-term safety or danger concerns.  I know we can always obtain Panacur off of legitimate websites, should our vet not be keen on giving it more often.  But then again, they may know of some health issues with giving it more often or being on it long-term.

Oh, and btw, I will say that we do like our vet and think they're good vets overall (they're listed on the rabbit-savvy vet list, after all, but they just don't seem to be as up-to-date on e-cuniculi treatment/medicines as I would like - for example, a few months back, they tried to mix things up to see if we would get better results by trying albendazole, but I remembered that you had pretty much advised against using any of the bendazoles, except for Panacur, so we decided not to use it.

Anyway, thanks again Dana!

ANSWER: Dear Paul,

Ponazuril is so new on the market, and so few vets have used it for E. cuniculi that it's hard to say which drug is better.  But if the Panacur isn't working any more, I'd certainly give the ponazuril a try.

Ponazuril comes in a very thick horse paste that needs to be diluted for a rabbit.  It's not flavored, but it doesn't taste bad, either.  You need a prescription to get it online or anywhere, and it's not cheap.  If you do get some, then let me know if you need instructions for dilution, and I'll be happy to provide them (my wonderful husband does this at work where he has a nice Mettler balance, which helps get things more exact).

I've known of bunnies to be on Panacur for life with no evidence of bad side effects.  So if he stays well on it, then you might ask the vet about keeping him on it, especially if signs of E. cuniculi return when he's taken off the drug.

I'm glad you didn't use the albendazole.  Many rabbit expert vets are simply taking it *off* their list for E. cuniculi because of its high toxicity, and because several sudden rabbit deaths have been linked to its acute toxicity.  Since Panacur (fenbendazole) works well, I would not ever risk using albendazole on a bunny.  Oxibendazole would be another good choice, but never albendazole.

Hope this helps!

Dana

---------- FOLLOW-UP ----------

QUESTION: Hi Dana,

Well, we spoke to our vet about wanting to try Ponazuril and he, somewhat reluctantly, gave us a prescription.  His main concern was that there simply wasn't enough information and/or studies out there in regards to Ponazuril and it's safety & effectiveness in rabbits.  But he did find a couple of anecdotal reports, wherein one rabbit saw some good results and another, who was given way too much of the drug, had some small results, while luckily, having no adverse effects from the "overdosing".

Anyway, my question now is about determining the correct dosage and dilution.  Our little guy weighed in at exactly 3 pounds, just over a month ago, so we're trying to figure out how much to give him, etc.  Our vet actually went ahead and gave us dosage instructions, but said it didn't need diluting, so I don't know about that and how it might compare to your dosage experience.  Anyway, the vet's dosage, using the 15% paste, was to give him .45 cc per mouth daily for 30 days (he said basically, it should be 50 milligrams per kg of weight).

Anyway, let me know what you recommend for dosage and dilution of the Ponazuril for a 3 lb. bunny.  I'm guessing you're talking about dilution of the paste with water.  Our little guy is just about to finish another 30 day cycle of Panacur, wherein we saw a little improvement the first week or so, but not much since then, so I'm about ready to try the Ponazuril, since it appears to be something different and safe to try for his e-cuniculi.  I figure we need to try and give him a 30 day break, in between ending the Panacur and starting the Ponazuril, if we can, in order to be easier on him, but maybe that's not necessary.  Hopefully, we can mix in a little of his favorite medicine additive, Children's bubble-gum flavored Benadryl, in order to make it more palatable, if we won't just lick it off a spoon, which he already does for the Panacur (and crushed Baytril tablets, too).

As always, thanks for the great advice and encouragement!  

Answer
Dear Paul,

I apologize for the delay in answering.  Your email caught me at the cusp of final exams, and I got buried in the crush.  :(

Here's what we do:

Marquis is sold as an extremely thick paste of a concentration approximately 150mg/mL.
(FYI, one mL (milliliter) is the same as one cc (cubic centimeter), the usual measurement
increment on a typical syringe). To be able to draw it up into a syringe, we dilute it with
distilled water.

By adding 2mL of distilled water to every 1 gram of paste, you get a suspension/solution of approximately 50mg/mL.  If your vet recommends a dose of 50mg/kg once per day, then that would mean giving your little guy (who weighs 1.35kg) 1.35ml per day.

The usual dose we administer is 20mg/kg of rabbit once per day for five days (for coccidia).  That means you give 0.4cc of the suspension for every kg of rabbit.  (One kilogram = 2.2 lbs.)  Dose ranges vary, since no one is really sure what's going to work, but I've heard of people giving 50mg/kg with no adverse effects.

You will need a very good balance to measure out the paste in grams, and your vet may have
such a scale.  Shake the suspension well before using.

Hope that helps!

Dana