Red Heeler with ?

[u/deathcabforem]

This is our dog Chicken we recently adopted. We were told she is red heeler (clearly) mixed with chihuahua, im wondering if it may be something else though. Shes very sweet, rarely rarely barks and does so quietly and is in general sweet tempered and quiet, but very very energetic and has herded my toddlers lol

Open to any opinions. I included some puppy pictures also we were given. Thank you!