Pet cried out on its last legs (8)

I believe the answer is:

decrepit

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'its last legs' is the definition.
I can't judge whether this defines the answer.

'pet cried out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'pet'+'cried'='petcried'
'petcried' is an anagram of 'DECREPIT'.

'on' acts as a link.

Can you help me to learn more?

(Other definitions for decrepit that I've seen before include "Worn and broken down by use" , "Worn out; infirm" , "Feeble - dilapidated" , "Impaired by age" , "Getting on" .)

I've seen this clue in The Globe and Mail.

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