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.
