Removing ping/icmp from a network

[Secure This <lists () securethis net>]

I have a variety of clients with data centres who all make use of 
icmp/ping to monitor their servers/appliances/devices (often with poorly 
configured snmp versions 1 and 2).

Could anybody kindly advise me of tools and strategies for minimising or 
removing the use of icmp/ping on a supposedly secure network?

Thanks in advance