There is in fact a difference as breed standards are not always the same from country to country. Note that majority of breeds in the US are actually from other countries wherein Americans have added their own twist to the breed and breed clubs in the US have re-written the breed standards to accommodate what they want the breed to look like and represent.
This is very true in my breed. In the North America and the UK the Miniature Pinscher is listed as a "Toy" breed when in fact it is one of the oldest of the "Terrier" family. Everywhere else the dog competes in the working group and is listed as a Terrier. Breed standards are written and re-written by the breed clubs and these standards can change quite often. Unfortunately we are left with in many cases, overly opinionated breed club individuals with far too much clout who may not like a color or a pattern to decide the standard and thus are able to change these things. Albeit, I am more interested in the breed standards set by the country of origin as these in most cases have been in place for many years and are not nearly as often changed.
This site may help clarify that there is a difference in American and German versions.
R-CK Kennels - German Versus American
As you will note, though there are some breed standard differences between the German and American version, both organizations through breed clubs list the standard pretty much the same.
Here is the German Standards and AKC listed standards at the bottom of the post.
*** Standards ***
The German standard FCI/ADRK
Shoulder height for males is 61 - 68 cm (24.01-26.77 inches)
61 - 62 cm (24.01-24.4 inches) small
63 - 64 cm (24.8-25.19 inches) medium height
65 - 66 cm (25.59-25.98 inches) large = correct height
67 - 68 cm (26.37-26.77 inches) very large
Shoulder height for bitches is 56 - 63 cm (22.04-24.8 inches)
56 - 57 cm (22.04-22.44 inches) small
58 - 59 cm (22.83-23.22 inches) medium height
60 - 61 cm (23.62-24.01 inches) large = correct height
62 - 63 cm (24.4-24.8 inches) very large
The AKC/ARC breed standard
Quoting:
"Size, Proportion, Substance --Dogs--24 to 27 inches. Bitches--22 to 25
inches, with preferred size being mid-range of each sex. Correct proportion is
of primary importance, as long as size is within the standard's range. The
length of body, from the prosternum to the rearmost projection of the rump, is
slightly longer than the height of the dog at the withers, the most desirable
proportion of the height to length being 9 to 10. The Rottweiler is neither
coarse nor shelly. Depth of chest is approximately 50% of the height of the
dog. His bone and muscle mass must be sufficient to balance his frame,
filing a compact and very powerful appearance. Serious faults--Lack of
proportion, undersized, oversized, reversal of size characteristics (bitchy
dogs, doggy bitches."