[gemy]

I think you need to wait a bit, and here is why. Start the obedience training, see how your heeler interacts with other dogs in that controlled environment. Along the way your trainer will get to know you and your dog. And will be another source for good advice.

As you know dogs have different personalities, and a dog with a high prey drive, that is not fully obedienced trained is a huge risk to a little Yorkie be it a full grown Yorkie or not. Even with full training there is still risk.

I do not have a heeler, but if you look in my avatar I do have 2 large breed dogs, and as such I monitor play time really well. Razzle and my oldest boy can and do interact really well together. But my younger female is never left alone with Razz, she has a large prey drive. One mis step if she chases Razz and she could at the minimum break a bone.

The other thing you can do is research up on the heeler. It's traits, personality etc.

Then think about if you would be prepared to crate either one or both dogs, when you are not at home, or at night when you sleep. Ensuring the pups don't go out into the backyard together alone.

The time you spend researching the heeler breed, the training, will also give you time to research good Yorkie breeders in your area.

And I know I see retractable leads out there on walks all the time, but I was taught they are only to be used for specific training commands in a controlled environment, not for taking your dog for a walk.

Best of luck