I also have a 17 inch screen and the header on the HOME page appears narrower than the body and the right margin appears narrower - so it must be the screen size. The alternate pages, however - are in perfect balance on my screen I don't like the color on the declaw site - so drab! Could it perhaps be shades of rose, teal or aqua? (picky picky!!)
All in all, the site is easy to navigate and very nice!! Loads of information and I have already used it several times as a reference to people for the lost cat poster.