Regularly come round about a dog (5)
I believe the answer is:
recur
'regularly come round' is the definition.
'about a dog' is the wordplay.
'about' becomes 're' (common abbreviation for 'with reference to').
'a dog' becomes 'cur' (cur is a kind of dog).
're'+'cur'='RECUR'
(Other definitions for recur that I've seen before include "Be repeated" , "come back to one's mind" , "Return to mind" , "Happen again (5)" , "expected to return" .)