If you read the AKC standard, spinoni must not have an undercoat:
A Spinone must have a correct coat to be of correct type. The ideal coat length is 1 1/2 to 2 1/2 inches on the body, with a tolerance of 1/2 inch over or under the ideal length. Head, ears, muzzle and front sides of legs and feet are covered by shorter hair. The hair on the backsides of the legs forms a rough brush, but there are never any fringes. The eyes and lips are framed by stiff hair forming eyebrows, mustache and tufted beard, which combine to save fore face from laceration by briar and bush. The coat is dense, stiff and flat or slightly crimped, but not curly, with an absence of undercoat. The Spinone is exhibited in a natural state. The appearance of the Spinone may not be altered. The dog must present the natural appearance of a functional field dog. Dogs with a long, soft or silky coat, the presence of undercoat, or any deviation of the coat is defined in this as well as excessive grooming, i.e., scissoring, clipping, or setting of pattern shall be severely penalized as to eliminate them from further competition."