Where did the Dog-people come from? In Dragon-ball there are numerous dog-people, one of which is the king of the world



There were other dog-people in the anime episode Plight of the children.  One of the orphans was a dog person, and one of the police was a dog person.

Where did they all come from?  Did someone, one day, breed with a dog, thus spawning this race of Dog-people?
In Dragon Ball universe Animals are different form our earth animals. Some of then can talk and even walk on two legs.Take Puar and Oolong as an example. Its never explained that why some dogs on Dragon Ball universe act like normal dog and some act as human. Not only for the case of dog, there are other animals too which behave in the same way.

Here is a link for the different species of animal appears in Dragon Ball Universe.

Its my own assumption that they can be alien on Dragon Ball universe from different planet. But there is no official words. 

Or it may be a plot hole that some animals talk and some can't.