Used to have animals outside - dogs? (7)
I believe the answer is:
shadows
'dogs?' is the definition.
(dog can mean to follow or shadow)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for shadows that I've seen before include "1960s band" , "They're cast by blocking the sun" , "Dark areas where the light is blocked" , "Dogs" , "Follows" .)