PostgreSQL 9.3: Dump a database excluding the data of some tables
I think you need to use --exclude-table-data=table option. From the docs:

--exclude-table-data=table
Do not dump data for any tables matching the table pattern. The pattern is interpreted according to the same rules as for -t. --exclude-table-data can be given more than once to exclude tables matching any of several patterns. This option is useful when you need the definition of a particular table even though you do not need the data in it.
To exclude data for all tables in the database, see --schema-only.