Because there is no specific information on how big the dog is, and height and length data is not available, I can only say a generalization, not absolutely sure. (There may also be bias due to the angle of the photo.)

Your dog should not be a terrier for the following two reasons:

1. It looks small. If you visually measure your dog's height, his head should be more than his knees, and he is a small dog. And China's current Chinese field dog, that is, the general size of the earth dog should be in the medium dog or medium to small. This is the main point.

2. Hair is longer than that of the Tudong. The Chinese field dog coat is generally very short. However, as Chinese field dogs are also divided into several types, some of them have a large amount of hair, but already due to the lack of attention of the Chinese people, there are fewer and fewer of them.

This dog's breed is a String (a cross between different dogs) and is a domesticated pet type that has been strung for many generations.

But skewers are easy to keep and smart, which is actually nice.

As for being bred to be a guide dog, like the OP said, that's not necessarily true. That one must have thought he looked a bit like a Labrador. But there are so many requirements for a guide dog, size, personality, obedience, etc. that must be taken into account, but you can never, ever tell from a photo.

If you have any questions about your dog, please feel free to ask me.

I hope this helps!