Jbun
This thread has some info about toltrazuril, including some input from a vet that has used it to treat rabbits.
http://forums.rabbitrehome.org.uk/sh...-Aware-of-This
You have to keep in mind that Dana Krempels is using Ponzuril at that dosage, not toltrazuril, as Ponzuril is what is available in the US. And even though they are a related drug, I don't know that you can fairly compare their dosages, without some sort of scientific study or other drug info saying that they have a comparable action at an equal dosage. It could be with ponzuril being a metabolite, that it requires a higher dosage to have an equal effect to the toltrazuril.
As for the dosages for other animals, what is the method of administration? I know in poultry that it is put in their water, so maybe this is the difference for the rabbit dosage, as rabbits will be given it by direct oral administration.
Personally, with the lower dosage coming from rabbit resources, as well as a scientific study having been done showing it's effectiveness at the lower dose, that is the dosing I would follow, unless it was proven to me ineffective.