DNS Monitoring and Alerting

[mush2020]

Does anyone know how to detect and alert on DNS all types of record change for domain.
I have name server in DMZ and ptr records are created for published services like email, ftp, web.
I manage and control my NS, ISP is authoritative for IPs allocated, but someone in the world creating PTR records identical to my domain published services.
 e.g. 123.123.123..123 pointing to my ftp.mydomain.com
I want to monitor and get alerted if there is unauthorized record created for mydomain.com
I don't have control on malicious threat actors, but at least if i get alerted i could report to take down such records.

Is there any Opnsense plugin to monitor or any external services to subscribe.

Thanks