Nameserver Checker
Solution 1:
Bind include a set of tools for testing configuration and zone files. The man pages of named-checkzone and named-checkconf should give you all the informations you may need.
Solution 2:
Ask a public recursive server for the records.
For example, if I just setup some record for randomtest.example.com on my server that's authoritative for example.com,
host -t any randomtest.example.com. [8.8.8.8][1]
will tell me if it is getting out to other nameservers on the internet.