Why are the breeds of dogs used as guide dogs?

Usually labs and golden retrievers. German Shepherds are sometimes too, but not as commonly.
K9 dogs
It is best to have a well trained golden retriever or a German sheperd
A good type of guide dog is a Golden Retreiver because the breed is loyal and easy to train.
A lot of the guide dogs are Labradors,Golden Retrievers and German Shepherds.Also lab and golden retriever mixes.

Note: only dogs trained by the Seeing Eye can properly be called "Seeing Eye dogs." The Seeing Eye uses only German Shepherds, Golden Retrievers, Labrador Retrievers, and Lab/Golden crosses. The generic term for dogs trained to guide the blind is "guide dog."

Labrador Retrievers are currently the most popular breed used for Guide dogs. Most programs use Labrador Retrievers, Golden Retrievers, German Shepherds, or crosses between Golden Retrievers and Labrador Retrievers as guide dog candidates. Some programs use Labradoodles, Boxers, or Chesapeake Bay Retrievers. It is extremely rare for a private trainer to train a guide dog. Since very few programs would accept outside animals for training, other breeds are very difficult to obtain.

These breeds are chosen for their biddability, intelligence, ability and willingness to work long hours, ability to tolerate stress, good health, and public acceptability or recognition.

Originally guide dogs were primarily German Shepherds. They were selected because they were available (this was right after World War I), they were being very well bred to work, could work very long hours, were easy to train, and were good at working out problems or situations for which they were not trained.

Later most programs switched to Labrador Retrievers because the German Shepherds were not suited for many clients. Shepherds require confident owners with some skill at training and handling dogs. They can be hard headed and become destructive if not given enough mental and physical stimulation. In more recent years their public image has also deteriorated because of poorly trained dogs biting people.

Other contributors have said:

• Any dog with a calm demeanor who has been trained to be a guide dog can be a good one. However, typically guide dogs are Labrador retrievers or golden retrievers because these breeds have ideal behavior and intelligence characteristics for guide dog work.

• In reference to whether a pit bull could be used as a guide dog:

It would be permissible in a legal sense, to train a dog like a pit bull as a guide dog if you were able to do such training on your own, or have it done for you.

The federal Americans with Disabilities Act gives tremendous rights to people using service animals. Service animals are not exempted from other local laws, including vaccination, leash, and breed ban laws. There is no certification process, since the use of service dogs varies so widely, from seizure alert dogs, to wheelchair pulling, to retrieving dropped items. So strictly speaking, yes, if a dog (of any breed) has the temperament to do guide work, under the ADA it would be allowable.

However, since local laws may ban certain breeds, such as pit bulls, it may be impractical to train such a dog as a guide since it couldn't actually be used.

• We commonly "see" labradors and retrieving dogs once used for retrieving during duck hunting. They are small, though large enough to do and go where we need at a sufficient pace.

• Regarding bulldogs as guide dogs:

1. Not really, I have not heard of it. One of the problems with having a bulldog as a guide dog is that it has short legs, not like the lab or German shepherd. Another is it has breathing problems. If you were a blind person, would you like to lose your guide early due to breathing problems? Most bulldogs have the problems. So, no, it is unlikely that the association will be entering bulldogs into the classes any time soon.
2. A bull dog is too short and very very few could meet the health requirements for becoming a guide dog. According to the Orthopedic Foundation for Animals, the bulldog is the most likely to develop hip dysplasia of any breed of dog. Of 443 bulldogs tested, 73.6% were dysplastic. Dysplastic dogs cannot be guide dogs.

• Regarding Collies as guide dogs:

Most guide dogs are trained by professional guide dog schools such as Guide Dogs for the Blind, the Seeing Eye, or Canine Companions for Independence. They use mostly labradors and golden retrievers. Guide dogs are usually not owner-trained. Guide dogs have to wear a large harness to assist their handler. Collies have long fur and this type of harness would likely mat their fur. Matted fur is ugly and often painful. Collies have a high maintenance coat and would likely be difficult for a blind person to care for as they can't see the problem areas and would have to do it all by feel. Collies are used as service dogs but I have never seen one as a guide dog.

• Regarding Italian Greyhounds as guide dogs:

They are too small to do the work. A variety I think, the most common used breed in my opinion is the Labrador retriever, they use that breed because it is a very sweet dog and is ranked number 6 in the top 10 smartest Dog Breeds.
golden retrievers. very smart dogs...
German Shephards, Labradors, Shetland sheep dogs, Rottweiler's, pit bulls, Dalmatians, plain collies.
Guide dogs for the blind must have a calm disposition, unshakeable confidence, and a level of self-awareness sufficient to guard the life of their person. German shepherds, Golden retrievers, and Labrador retrievers are well-known to have become stellar guides.
Mostly Retrievers and Sheperds.
Any dog can do service work, but the most used breeds for seeing eye dogs are Labradors, Golden Retrievers, and German Shepard dogs.
Guide dog candidates must be large enough to perform the essential functions of a guide dog and meet health, temperament, and trainability requirements but there is no official restriction on what breeds might be used.

Members of breeds banned by local ordinance or state statute are not generally good candidates because guide and service dogs are not exempt from local animal control laws.
I have mostly seen labs (labrador retriver) doing this important job for blind people. Other possible breeds for doing this important job are German Shepards. Mostly they are based on how smart the dog is and how well it does with the person its assigned with, and how well it does staying focused on it task and focused on its training.
The commonest breed is the Labrador - known for their intelligence, quick learning and gentle nature. Aside from that - the Golden Retriever and German Shepherd are popular choices.