What are the different varieties of rottweilers? Example German rottweilers\ American rottweilers……Which ones grow taller?
The only difference is whether a line is bred to meet akc standard http://www.akc.org/breeds/rottweiler/index.cfm or FCI standard http://www.usrconline.org/breedstand.html
For a male
AKC max standard height is 27 inches
FCI max standard is 68 centimeters = 26.7716535 inches
There is no big difference between them in height but whether the dog in question is closer to the min or max height or under/over standard depends on the line. In germany they only breed dogs that fall within breed standard, here they can and often do breed anything with papers.
German lines are often considered ‘sharp’ or ‘hard’ compared to many american lines, in germany they have to earn the right to breed with fitting within the confirmation standard and with working ability/temperament testing/endurance testing (required titles) and breed reviews/ratings. They are generally more muscular than american lines and have more drive making them not the best pet for an person without experience with such a large dog. American lines look more refined and smoother bodied, sleeker.
Coat can vary in how far away from standard it is allowed to be, a wavy coat or overly long coat is a fault. If a dog of either line is very nice they can still win dispite having faults, few dogs are perfect. Generally most responsible breeders adhere to trying to produce pups that are as close to standard as possible. Form follows function, too much variancy from the standard can affect working ability or health ie oversize is more risk of hip problems.