Can I monitor another server using keepalived?

I have 2 HAProxy linodes running as load balancers in front of my DB nodes . I want to use one as MASTER and the other as BACKUP to maintain a High Availability setup. (I can't use a Linode Nodebalancer for reasons I won't get into here.) However, I can't use the IP Failover that Keepalived is designed for, since we are using the Toronto Datacenter and IP Sharing is not available (yet).

What I would like to do is to run keepalived on a separate server (my web facing server), and use a script to continuously check whether that server can connect to the MySQL DB through HAProxy-1 (master). If HAProxy-1 goes down or the connection to the DB is interrupted for any reason, keepalived would run a script to update my web server config to set the DB IP to HAProxy-2 (backup).

Can anyone point me to a tutorial or example configuration for this? I have been fiddling with the keepalived configs, but I cannot get it to work. It appears that keepalived on the separate server doesn't understand that it is monitoring a remote service, so it is advertising itself as DOWN instead of the remote HAProxy server. Every keepalived example I have found only has one "instance" config on each server (to monitor itself), rather than 2 like I am trying to do…

Maybe this is just what keepalived does - in that case, is there a different monitoring tool that can easily do this?

Thanks in advance for your wisdom and guidance. :)