Mad Dog losing his head, in a state? (5)
I believe the answer is:
nutty
'mad' is the definition.
(I've seen this before)
'dog losing his head in a state?' is the wordplay.
I cannot really understand how this works, but
'head' could be 'nut' (informal term for somebody's head) and 'nut' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for nutty that I've seen before include "19 [LUNATIC]" , "Eccentric - like nougat?" , "Like cobs, brazils, etc" , "Round the bend?" , "Crazy -- tasting of almonds" .)