NOT urgent: Rabbit Needs Fenbendazole every 2 months. Is this safe?

Question
Hello!

Thank you for answering my question.

I'm a member of a Rabbit Rescue. My personal rabbit, a 3 year old neutered male Mini Rex Mix, has a highly sensitive digestive system. Any tiny bit of fruit or grains gives his gas.
Also, Patches contracted Pin Worms from a foster bunny that was found outside.

We have not been able to eradicate the pinworms, no matter what we've tried. The result is that Patches has to be treated for pinworms with fenbendazole every two to three months, once a day for three days. If I don't treat him, he gets gas every single day non-stop. Before we found the cause, he got gas every day for 16 days. He must have been so miserable.

My question is, is there a likely danger in giving fenbendazole every two months for life? If so, is there any dietary supplement that can help protect him?

Thank you so much!

Answer
Dear Bethany,

I know of many rabbits who are constantly on fenbendazole for E. cuniculi, and they don't seem to have problems related to the drug.  Some of the benzamidazoles are toxic to the bone marrow and can cause damage.  But of the three commonly used in rabbits, fenbendazole is one of the more benign.

If it keeps Patches happy and comfortable, I would not worry too much about using it once a month.

Dana