Relentless - Dean Kootz

Bestselling novelist Cullen "Cubby" Greenwich is a lucky man and he knows it. He makes a handsome living doing what he enjoys. His wife, Penny, a children's book author and illustrator, is the love of his life. Together they have a brilliant six-year-old, Milo, affectionately dubbed "Spooky," and a non-collie named Lassie, who's all but part of the family.
So Cubby knows he shouldn't let one bad review of his otherwise triumphant new book get to him — even if it does appear in the nation's premier newspaper and is penned by the much-feared, seldom-seen critic Shearman Waxx. Cubby knows that the best thing to do is ignore the gratuitously vicious, insulting, and inaccurate comments. Penny knows it; even little Milo knows it. If Lassie could talk, she'd tell Cubby to ignore them, too.