This is especially useful to blind people, who use to dogs to help and guide them around places. Farmers also find dogs useful to protect there farm animals. Cats on the other hand, are not a great source of protection. They can not scare off or defend people. Lastly, dogs are more passionate and active.
Dogs miss there owners more than cats.
They get attached emotionally and psychologically to their owners. They have a harder time dealing with there owners going away. Dogs always want to be petted and played with . You can take dogs to keep you company on walks and toss balls, sticks, and frisbees for them to catch and bring it back to you. Cats on the otherhand are heartless.