A pettish, low-down dog? (5)

I believe the answer is:

corgi

I'm a little stuck... Click here to teach me more about this clue!

'dog?' is the definition.
(I know that corgi is a type of dog)

I don't understand the rest of the clue.

(Other definitions for corgi that I've seen before include "The Queen's favourite?" , "pet in 9 [CARDIFF]?" , "Royal canine" , "Queen's dog?" , "found in the kennels" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app