How to check DNS cache status in Mac OS X

As a follow-up to How to Flush DNS Cache in Mac OS X I have received a question:

how do I know if it worked? In other words, is there a way to check if the DNS cache is cleared?

To see the DNS cache status you may run

sudo killall -INFO mDNSResponder

Thus the SIGINFO signal will dump a snapshot summary of the DNS internal state to

/var/log/system.log

Voilà :-)