I would think that if they were closely related, they would at least be a cross of the same breed.
Black is a color and not a breed. Appaloosa horses can be black.
If you mean the same breed, not always.
Usually. The breed in America is usually the American Mustang.
Yes they can, it is called In-Breeding, although many players do like and do not breed In-Bred horses, Non-inbred horses are called NIB's.
The Spanish Riding School in Austria.
The Arabian horses order is Mammalian. Which is the same for all horses no matter the breed.
Yes and no. It depends on the type - Indian Horses are said to be horses with significant Iberian (Spanish) blood in them whilst mustangs are more of a mongrel breed with several different influences. However, some authorities will say they are the same breed.
Pinto horses are colored like the paints but have their own breed registry. Also, pintos are horses of any breed with paint coloring.
A Prezwalki horses diet does not differ from any other horses diet. In other words, the breed can eat the exact same as any other breed.
Uh, if they didn't breed, how are they supposed to have more sea horses? Yes, sea horses breed.
A horse breed is a group of horses that all have similar characteristics, such as coats, confirmation, size, ect. They have to be purebred. Cross breeds can become a breed if they are bred for several generations with the babies all having the same characteristics.
All horses can cross breed with each other.