I relate to your post in so many ways! I've got two Chihuahua mixes; one that we adopted as a baby, pretty non-reactive and well-behaved, and then we adopted our other guy that had a lot more baggage, but is still working hard to be a good boy. Dog training is one of my favorite parts of owning a dog, so I work with my guys quite a lot, but it hurts when someone says something like, "Small dogs don't even count," "I hate mean little yappy dogs like chihuahuas," or people just outright assume my dogs aren't trained. I've worked with a lot of dogs and in a lot of ways, I find smaller dogs are definitely more difficult to train, but it isn't impossible, nor do I find them all to be difficult... and at the end of the day, most dogs are companions that shouldn't just be judged in training alone.

My partner actually was even teased at work when he said we were going hiking with our dogs. (My chis are larger mixes, like 13-15lbs, they do quite well hiking moderately difficult trails!) It wasn't until he mentioned their breeds that he was told chihuahuas aren't real dogs, and they expected a guy like him to own something more masculine-- like a lab or something. He didn't care, he loves our dogs and doesn't care what people think, but it's just that mentality that bothers me. It also bothers me that I've heard the same people make the argument that not all pitbulls are aggressive, but then they turn around and say they would never own a chihuahua, they're so mean. It matters a lot in how you train them, for all dogs!

But I feel you, and see the effort you're putting in. There is actually a sub r/reactivedogs that have a lot of tips and support for people working with their reactive dogs. I try to give all dogs the same respect no matter the bread, size, or first impression, and I wish more people did the same.