Replace her ratty bloodhound? Not any time soon! (4,4,4,6)

I believe the answer is:

dont hold your breath

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'replace her ratty bloodhound? not any time soon' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'replace her ratty bloodhound?' is the wordplay.
'replace' is an anagram indicator (I've seen 'replaced' mean this).
'her'+'ratty'+'bloodhound'='herrattybloodhound'
'herrattybloodhound' anagrammed gives 'DONT HOLD YOUR BREATH'.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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