Mother takes in dogs (8)
I believe the answer is:
mastiffs
'dogs' is the definition.
(mastiff is a kind of dog)
'mother takes' is the wordplay.
'mother' becomes 'ma' (Ma is another word for mother or mum).
'takes' becomes 'stiffs' (I am not sure about this - if you are sure you should believe this answer much more).
'ma'+'stiffs'='MASTIFFS'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for mastiffs that I've seen before include "man's best friends?" , "Powerful deep-chested dogs" .)