Blocking Certain DNS Queries

Is there anyway to throttle UDP DNS queries for “.” in the Mikrotik firewall?

http://isc.sans.org/diary.html?storyid=5713

There is an example at the bottom of page here for IPTABLES:

http://www.secureworks.com/research/threats/dns-amplification/?threat=dns-amplification

I would like to allow them through my gateway Mikrotik router but drop them if they excede a certain rate.

Matt