Why not change your log reading tool to exempt the above pattern from the alerts? If the alert is sent every time the files change at all (ignoring the specific changes) I would say that's a bad alerting mechanism...
You can make sshd log to another facility, though:
etc... Check the man page for sshd_config for details.
If you choose one of the local facilities, make sure your syslog.conf is configured to send it somewhere.