postgreSQL hot_standby pg_dump on slave

I have master-slave (hot_standby) pgsql configuration and I want to make backups from one of my slaves. I don't want PITR, just good old database dump.

I switched to postgres from MySQL. With MySQL replication I made backups from slave with these steps:

1. stop slave;
2. perform mysqldump
3. start slave

Can I do something similar with postgres?

I tried pg_dump on slave, but it returned errors:

pg_dump: Dumping the contents of table "news_event" failed:   PQgetResult() failed.
pg_dump: Error message from server: ERROR:  canceling statement due to conflict with recovery
DETAIL:  User query might have needed to see row versions that must be removed.

Also, pg_dump works good on master so I can do backups on master server, but I prefer to make it on slave.