Zodiac topical treatment for cats contains the active ingredient S-methoprene, which did not cause any serious side effects in a lab test on rabbits (Hallesy and Hill1973). However, it can cause a toxic reaction in rabbits sensitive to the drug.
Other Zodiac products contain pyrethrins, which have caused toxic effects on some rabbits when applied topically. (I use pyrethrin sprayers in my barn, which have not caused any health problems in my rabbits).
Zodiac flea powder contains Carbaryl, a produce which has been used for many years on rabbits. I used it for many years without any rabbits having side effects, however, as with all drugs, side effect shave been reported in individuals sensitive to Carbaryl.Symptoms generally cease once the product is washed off the skin.
In rare cases, severe burning and skin reactions have been reported from Revolution. Illness/death was reported in a few rare cases of rabbits licking Advantage off another rabbit.
There is no product that is completely safe. I highly recommend consulting a vet before giving a rabbit any flea treatment due to possible toxic effects of the drugs.