Eg cockapoo, grumpy about being confined to bed (10)
I believe the answer is:
crossbreed
'eg cockapoo' is the definition.
(cockapoo is a dog crossbreed)
'grumpy about being confined to bed' is the wordplay.
'grumpy' becomes 'cross' (synonyms).
'about' becomes 're' (common abbreviation for 'with reference to').
'being confined to' indicates putting letters inside.
're' inserted inside 'bed' is 'breed'.
'cross'+'breed'='CROSSBREED'
(Other definitions for crossbreed that I've seen before include "Mate (two different species)" , "ass, possibly" , "lurcher" , "Mongrel" .)