Never work with children or dogs. It's classic advice for actors who want to avoid being upstaged, and it holds true even if the dog is played by a human. In Buffalo Theatre Ensemble's current production of Sylvia, the title pooch is portrayed by Allison Latta, who scampers away with the show. This bittersweet domestic comedy hangs on author A.R. Gurney's conceit of making the dog a fully realized speaking character. A stray with a name tag, Sylvia is picked up in a park by Greg (Robert Jordan Bailey), a man in the throes of a midlife crisis. He's immediately smitten with her, but when he takes her home she pees on the carpet, sheds on the couch, and otherwise infuriates his wife, Kate (Christy Bell), who sees her as a threat to both their empty-nest lifestyle and their marriage. Although Greg comments more than once on Sylvia's "cute butt" and is warned by another dog owner (Christopher Popio) about the dangers of thinking of her as a woman, she's more than a simple stand-in for a human lover: besides exploring middle age and marriage, Gurney is testing the outer bounds of attraction. There's little in this romp that will challenge the audience, but it appears to have been the inspiration for Edward Albee's much sharper and darker take on the subject in The Goat or Who Is Sylvia? Creative lighting makes a couch, table, and three screens work as a park or therapist's office as well as a Manhattan apartment, and Sylvia's costumes--including a showstopping just-at-the-groomer's getup--deserve a treat. This is not the strongest acting I've seen from the Buffalo ensemble, but Latta's great and anyone who's ever had a dog is likely to be charmed. Sylvia, directed by Kurt Naebig, continues Thursday through Saturday at 8 and Sunday at 2 through June 5 in Theatre Two at the McAninch Arts Center, College of DuPage, Park and Fawell in Glen Ellyn. Tickets range from $23 to $26; call 630-942-4000.