Resto druids are, as far as I know, the only healerclass that lacks a dedicated interrupt. Let's be fair though, they compensate it with mobility and great healing.

Does balance druid have an interrupt?

Balance Druids finally get a legitimate interrupt!

Does guardian druid have an interrupt?

Additional Utility for Guardian Druids

This can double as an area of effect interrupt in dungeons, against enemies who are not immune to disorients.