Like canine amputee in yard? (5,4)

I believe the answer is:

three foot

'like canine' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'amputee in yard?' is the wordplay.
'amputee' becomes 'three' (I can't justify this - if you can you should believe this answer much more).
'in yard?' becomes 'foot' ('foot' is part of 'yard').
'three'+'foot'='THREE-FOOT'

I've seen this clue in The Guardian.

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