Based on the information provided, the following pets are suitable for the poor:

1. Chihuahua: the smallest dog in the world, suitable for the poor.

2. Yorkshire: petite, second only to the Chihuahua, suitable for the poor.

3. Poodle: by far the most popular pet dog in the world, suitable for poor people to keep.

4. Pomeranian: a small dog with a cute appearance, ideal family companion dog, suitable for poor people to keep.

5. Maltese: long and slender, with a long coat of silvery-white silk luster, elegant and charming, suitable for poor people to keep.

6. Butterfly dog: small dog, agile and adaptable, suitable for poor people to keep.

7. Pug: small dog, even as an adult, will not grow too big, suitable for poor people to keep.

8. Miniature Schnauzer: strong, active terrier, alert and positive character, suitable for poor people.

9. Miniature Doberman: Lively, cheerful, strong, walks with a big swing, very popular, suitable for poor people to keep.

The above are some types of pet dogs suitable for poor people to keep.