Here is one of my students and her Chihuahua. Adopted from a rescue, with an unknown history, this dog started out with very little to work with: fearful of humans but playful with the family dogs; mild interest in treats; mild interest in playing fetch with the owner; afraid of being touched by a human, including the owner; afraid of guests; couldn’t walk on a leash and terrified of a collar; and didn’t want to walk on wet grass. When I first arrived, she ran when I was invited in the home and hid in the living room. I could only get within about 15 feet from her, otherwise she would run away. Very worried if we made eye contact. No scars, no injuries, nice coat, healthy appearance. Diagnosis? This dog was not abused, but the early puppy socialization with humans was neglected.
This dog is a Project Dog, meaning a dog that will take a long time to turn around, which includes extra training time and expenses for the owner.
Here is a picture of where we are today…

She will now allow the owner to hold her in her lap and isn’t afraid of being petted, and isn’t shaking and trembling all the time… She is panting because this kind of work is tiring; that is not her baring her teeth. She doesn’t have her tail tucked anymore. You can see her ear position isn’t flat back on her head, but also not perky. We (thankfully) now can have a collar and leash on her for her safety. We are halfway through our longer-term goals, so the Project isn’t finished.
So, she is still afraid, but better than when we started.
I view a Project like this as if presented with a huge knot. How are you going to unravel that knot without harming the cloth and materials that make up the knot? At the start, everything you try scares the dog, even the first treats offered. Yeah, it has been that kind of dog. This type of Project Dog will always test your animal welfare ethic, which should be: Do No Harm.
What I do is test various ways of picking this and that thread on the knot, a little bit at a time. If you go too fast, you will damage the material. If you go too slow, then maybe you just give up and the knot is never unraveled: that is not an acceptable and ethical outcome.
In this case, the concern is that if she got out the front door, maybe she would possibly run away and perish in our desert environment. So, leaving the knot “as is”, meaning giving up on the dog, isn’t a humane solution.
We have come a long way. You can see she is still fearful and stressed, but this is what incremental progress looks like.
What wouldn’t have worked? Well, any kind of rush job where someone promised they could fix this dog in a week or two. Unfortunately, that describes most dog training programs.
These little dogs deserve the same kind of effort as the big ones. They have as much intrinsic value, and the same affection by the owners, as the bigger breeds.
I hope this gives you an idea of what might be done if you have a dog like this, big or small, and the kind of patience and investment it takes.
Plan accordingly.