It may be only mid-May, but the "dog" days are already upon IL's New American Theatre. That's because A.R. Gurney's canine comedy, Sylvia, opens there May 15 for a run through June 7.

Katheryn Phillips will play Sylvia, the "beautiful, frisky young blonde" who picks up Greg (Gary Wingert) in the park. Sylvia, of course, is a dog -- a pet who ends up coming between Greg and his wife, Kate (Elizabeth Muckley). Rounding out the cast is Lance Retallick, who plays an array of roles, from a philosophical dog lover to Kate's fellow Vassarite.

In 1994, A.R. Gurney received a Lucille Lortel Award for his body of work, including such comedies as Love Letters, The Cocktail Hour and The Middle Ages. His latest, Labor Day, starts performances this month at Manhattan Theatre Club, where Sylvia premiered in 1995.

NAT producing artistic director William Gregg helms Sylvia, which features costumes by Dana Tinsley Harnish, sets by Noel Rennerfeldt, lighting by Eric Stehl and sound by David W. Mauer.

For tickets ($18-$21) and information on Sylvia at New American Theatre, 118 North Main St., in Rockford all (815) 963 1060. -- By David Lefkowitz