no longer URGENT: Ivermectin sensitivity/overdose treatment info needed

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tonyshuman

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Hi, if anyone has had a rabbit that had a reaction to ivermectin due to hypersensitivity (dutch rabbits, blue-eyed rabbits, collie dogs even) or overdose and the animal was treated successfully, I am in dire need of info on this subject. My Tony needs the info ASAP. I have read just about everything online, from Medirabbit to this site to etherbun to just plain old google searches to the scientific literature.
 
[align=center]Sorry, I do not information either.. =( Sending good thoughts to Tony, hope all goes well!
 
Thanks for the comments guys. It seems that recovery for ivermectin reaction typically takes 4-7 days because the drug stays in the system for so long. In addition, the drug is eliminated from the body by pooping, so the fact that he hasn't been pooping or eating is a concern. He's being watched carefully and kept in a warm, high oxygen environment. He also is getting IV fluids. They're going to try to do a nasal tube to get some critical care into him. They did a charcoal enema to try to purge some of it from his GI and it was productive but with no food into him since last night 9pm there is little to poop out.

We're also doing an experimental treatment where a fatty solution is infused IV. The drug is also very fatty so this solution will help get the drug out of the blood. It has been used in dogs with similar toxicity and some pilot studies of rabbit poisoning with other compounds.

Most times, treatment of ivermectin overdose or sensitivity in rabbits is done with just IV fluids, oxygen, maintaining body temp, and an anti-seizure drug. I hope that he can make it long enough to eliminate the drug from his system and that this experimental treatment makes it eliminated faster.

This is a 100% nightmare and I really want to make it clear that nobody should give ivermectin to a rabbit with dutch in their background unless under the direct supervision of a vet, ie in the vet's office, with the vet monitoring them for 6+ hours after administration. Tony was fine up until several hours after administration and it seems that the bad effects peaked (hopefully) around 24 hours after administration. It should be avoided in dutches at all costs.
 
[align=center]Why are dutches so sensitive to ivermectin if I may ask?

I'm glad to know this for the future.. but I wish you weren't going through this to find it out..

I really hope Tony gets better, this must be so hard =(
 
The supposition is that dutches have a mutation in a protein that is part of the blood-brain barrier. A lot of herding dogs, like collies, have this mutation too. The mutation allows ivermectin to get into the brain, and it causes lots of problems there. It is well known that you shouldn't give ivermectin to herding dogs, but it's not as well documented in rabbits that they have this mutation and have bad reactions. Not all dutches will react badly to ivermectin, but the potential risk is so great that it's not worth testing. Other rabbits that often have adverse reactions to ivermectin include certain coat colors, especially ones related to the vienna gene, which is also related to the dutch genes.
 
It's interesting to note that some humans have the same gene mutation and will suffer the same sensitivity reaction.



Hope Tony is still hanging in there today. :pray:
 
Thanks guys. They did two courses of the lipid infusion treatment last night and got a feeding tube into him via the nose. He has improved a lot. He pulled out the feeding tube on his own early this morning and is eating critical care on his own, and pooping. They aren't doing any more lipid treatment because of concerns about giving him too much lipid in the blood. He's still on IV fluids and in the incubator to give him extra O2. He's been moving around a bit and is almost holding his head up. It's still at a bit of a downward angle.

We went and saw him this evening and took Muffin. While we were there, he ate a lot of critical care, pooped a couple times, and snuggled a bit with Muffin. The vets are doing continuing blood work on him to make sure he's doing ok as he gradually eliminates the drug from his system. He was messing a bit with his IV tube and tried to clean his face and his bum while we were there too. I don't want him to mess with the IV catheter of course, but it is a bit of his personality coming back. Tony hates to be dirty or have things on him that aren't normal.

Muffin also was better off for having seen Tony. She's been normal but depressed--hiding a lot, not eating as much, not eating her cecals. When we got home she flopped out so I think seeing him put her at ease. I think Tony was improved by having her there too--he did all of those active things when Muffin was out of the incubator, but it seems like a bit more activity than he had been having before.

Since he's still not quite able to eat and drink on his own normally, he'll be staying at the vet's for a bit longer. The hope is that we can bring him home tomorrow. I think he's out of the worst of it and is past the "come in now, he's crashing" phase. That is so hard to deal with and I am sure that the lipid treatment is part of why he has improved so quickly. Oftentimes it takes days of being comatose or near comatose for animals to come out of this.

Thank you guys all for thinking of him.

It's terrible to think of a person having this reaction, especially because it is thought of as a "safe" drug. The effective dose and the doses that cause adverse effects (in a non-sensitive individual) are very far apart. I did some math today and although Tony and Muffin might have gotten 10-15 times more of the drug than was needed, the level at which adverse effects occur in normal rabbits is around 2000 times more than the effective dose. I just didn't take the "may cause adverse reactions in dutches" warning seriously enough. Usually adverse reactions occur in less than 1% of any individuals who take a drug; so I assumed that the increased likelihood was not so great. I think a more accurate statement would be "very high likelihood of life-threatening complications in dutches."
 
I was thinking it was more dangerous for blue eyed whites too. So sorry about what you've gone through.
 
oh no i just saw this..!! oh please tell me hes doin even better today!!..ive worried about Ivermectin myself when ive given it to my buns...ive never heard about dutches having issues with it..might wanna put a thread on here somewhere stating this ...cuz im sure not many know about it..sending u and urs big hugs cuz i know u need it...and squeeze Tony for me too.
 
Bebe is a Holland Lop, and had a reaction when I gave her Ivermectin, and an injection of some Imectin to treat for mites. For several days she refused to eat and poop. Lucky for me, Bebe pulled through and never had any more problems. I suspect the Ivermectinhad an expirydate when it was used.
 
Thanks for the good wishes, guys. Overnight, Tony didn't have much change. They think he's been experiencing blindness due to the drug, which is common and often goes away once the drug is cleared from their system. This is making him quite depressed and less active, which is worrisome. We want him to be his sassy self again so that we can make sure he's not depressed from the drug itself. Ivermectin can make them less active and quieter than usual, so I hope this reduced activity is because he's confused about what's going on rather than a relapse into the bad effects of the drug.

Luckily, he is eating on his own and even ate solid food (veggies) last night. They still want to keep him on IV fluids and will not do another lipid treatment unless he regresses. I think the chance of him going back into a very critical state is low, but still possible, so it is also good that he is there in case that happens. Of course, I want him home so he can be in comfortable surroundings and with his Muffin, which I think would improve his mood, but I don't want to take him home until he doesn't need the IV anymore and seems further away from crashing. His heart rate is still a bit low and he had low potassium, which they did correct with the IV fluids, but he is still holding his head funny--kind of in a nose-down tilt position. The recovery is very slow and incremental it seems so it is frustrating in this periods where we're not seeing improvement for 12-18 hours at a time.

We will be visiting him later this evening again to see how he's doing and let him and Muffin visit a bit.

Once I have the wherewithal, I am going to compile all the incidences of ivermectin toxicity in rabbits that I can find. I really would like to know how common it is for this reaction to occur, since it seems to be much more common than we think of. I also am hearing about a lot of breeds that are supposedly prone to it, and looking into the genetics of these breeds. For instance, Dutch coloring is recessive, so a bunny can be a Dutch carrier without showing the characteristic pattern. Oftentimes a Dutch carrier bunny will look like a hotot, depending on what other genes they have. Vienna marking is a gene that produces a dutch-like pattern or white spots when the animal is heterozygous for the gene (this would be like Tinysmom's Sport, who had an ivermectin reaction), a blue-eyed white bunny when the animal has two copies of the recessive gene (these bunnies are also prone to neurological problems even in the absence of these drugs), and a normal bunny when two copies of the dominant gene are present. I have heard of it showing up in many different breeds, most often those where blue-eyed whites occur and dutch mixes.

The fact that Bebe had a reaction and she is a solid-colored Holland is interesting because presumably she is not a carrier of either the recessive vienna gene or the dutch gene because she would have some white spots if she were. However, she could be a carrier that just doesn't show white spots.

Ivermectin reaction is certainly something all dutch, broken, and vienna bunny owners should know about, and hopefully all bunny owners. I am starting to take the opinion that I will not be administering any medicine beyond simethicone and maybe aspirin to my bunnies without a vet's direct supervision. It's hard because I try to be sensitive to other members' financial situations, and thus look into these cheaper at-home treatments, but really medicine is not something we laypeople should be messing with. The cost of a bad reaction is at least 10x the cost of a vet-administered treatment, and in the case of ivermectin, the chance of a bad reaction is greater than we think. I don't know what the actual incidence of it is in normal or Dutch and vienna carrier bunnies, though.
 
the other thing to think about is ..since its packaged in a large amount for a large animal the actual medicine isnt consistent thru the whole tube so could we overdose a bunny even giving the appropriate grain of rice size amount.if that grain has a too large amount of medicine in it?...and would overdosing a rabbit with Ivermectin have the same symptoms as a sensitivity to it?..so are we really sure that certain buns are sensitive to the medicine ,,maybe we didnt administer it properly or maybe the tube of medicine wasnt consistent.?



 
That is a good point, Lisa. Overdose has the same symptoms as sensitivity, and would have the same treatment. I have read a story of a lab that overdosed on ivermectin by eating an apple slice covered in the paste that was meant for a horse but dropped on the ground and promptly snarfed up by the dog. He had the same symptoms and treatment. Labs typically are not sensitive to ivermectin. Although the amount I gave was only 10-15 times more than the required dose, it is safe up to ~2000x the required dose in non-sensitive bunnies. Case in point: Muffin got a bit more than Tony and has had no adverse effect. I have heard that the tubes can have locally high concentrations because you're expected to give at least 1/5 of the tube at a time, not just a tiny bit.
 
I believe that Kathy Smith was looking into doing some research on Ivermectin sensitivity - you might try contacting her.

Very glad to hear the promising prognosis.

Pam
 
He did not get to come home today, unfortunately. He is still improving and really seemed like he was getting his personality back when we went to see him today. He was grooming himself, moving around, responding to sounds and light, and trying to chew off his IV tube. He is still a bit weak and doesn't move around great yet, and did have an episode of tremors while we were there. His head is still not quite flat at rest, but he can pick it up fully. He even cleaned his face with both paws while we were there. I think he likes to clean himself when Muffin's around to make himself look more presentable for her.

He's eating critical care and solids on his own, although he's still on IV fluids, and he had a bit of a gut slowdown so they've put him on some motility drugs for now. That has seemed to help. In this case I am not worried about the motility drugs causing any problems because any reduced fecal output in his case is going to be from stagnant GI activity rather than a physical blockage. He really looks a lot better and is acting like a bunny, like himself, much more. He's getting babied by the staff with veggies and fruits too.

The vet said they'd start working on discharge instructions and that we might be able to pick him up tomorrow if he continues his course of improvement. I wouldn't want to have him at home if he were still experiencing tremors, not blinking enough (he still isn't doing that quite enough so they are adding eye drops), or not getting enough fluids. With luck he will be ready to come home some time tomorrow.

It is so good to see him "back" and I feel so lucky that we've made it through the worst of it (at least I think and hope). Thanks guys for thinking of him.
 

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