The little dog, an animal, might be on hand (6)
I believe the answer is:
puppet
'on hand' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'the little dog an animal' is the wordplay.
'the little dog' becomes 'pup' (short for puppy).
'an animal' becomes 'pet' (pet is a kind of animal).
'pup'+'pet'='PUPPET'
'might be' acts as a link.
Can you help me to learn more?
(Other definitions for puppet that I've seen before include "It's worked with strings" , "Small figure of a person operated with strings" , "Doll controlled by strings" , "Doll on a string or rod" , "Toy (with strings attached?)" .)