Apex domains cannot have CNAME records.
Question and response
Question
dig zoodom.gov.do. NS
Answer
zoodom.gov.do. 4 NS ns2015.ifastnet.com.
zoodom.gov.do. 4 NS ns1015.ifastnet.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0