I'm sure your dog is lovely, and it's not against you in particular. But dog breeding is genuinely harmful for the poor animals, especially when it affects their size and/or morphology a lot. Mongrel dogs tend to be healthier in general, mostly because it makes them more resistant to a lot of inbreeding health problems.

The human equivalent would be to make redhead dwarves selectively mate for generations just so you can have steady supply a big tiddy dwarf GF. It's all good from the outside, but that's not exactly an ideal situation for them, even without talking about mental issues.

I may be a bit dogmatic on this, but really if you want what's best for dogs, breeds are not what you're looking for.

Is it also comparable to specifically breeding for one with down syndrome because the baby ‘looks cute’?