ns2.thebestpetstuff.com has no AAAA records.
Question and response
Question
dig ns2.thebestpetstuff.com. AAAA
Answer
ns2.thebestpetstuff.com. 5 CNAME thebestpetstuff.com.
Authority
thebestpetstuff.com. 2203 SOA ns-139.awsdns-17.com. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0