Woof! Winona Ryder ain't the only celebrity in the dog house these days. Last week, Sharon and Kelly Osbourne never showed up at their own book party for Bark at the Moon: The Official Osbourne Pet Book (Pocket Books). An art gallery in West Hollywood was crammed full of stars and their pets — from Backstreet Boy A.J. McLean and his bulldog, Tank, to Survivor vixen Jerri Manthey and her dustmop, Gidget. But Ozzy's ladies were no shows. What gives?

Turns out, the overbooked Sharon was at the VH1's Big in 2002 Awards, where she accepted the "Strange But True" trophy for MTV's The Osbournes. Her guests were disappointed, but supportive due to the matriarch's medical condition. "I would love to meet the Osbournes," said American Pie starlet Shannon Elizabeth. "Sharon's a great lady. But she's only got a few good hours in the day right now, and she's got to take care of herself. That's what's important. She comes first."

Exorcist diva Linda Blair — looking fully possessed of herself in a devilish red pantsuit — was feelin' very sassy. "We've all gone to the dogs here in Hollywood!" the animal lover laughed, gesturing to the menagerie of pups, parrots, etc. all around us. So what's her Osbourne connection? "There's a famous picture of Ozzy holding me up in the air at a concert years ago," she grinned. "He was a big Exorcist fan." Hmm... Now why doesn't that surprise me?

Later, one gossipy guest — who dressed his teacup poodle in a blue Burberry cap! — told Party Boy: "You just missed David Faustino from Married... With Children. He left early because his big brown mutt was dragging him across the floor. It kept getting frisky with some of the other dogs!"

Photographer Chris Ameruoso — who snapped Ozzy's pets for the book — is used to animals' lack of social grace. "I've learned that the Osbournes really love animals — and chaos," he laughed. "They have 10 dogs and five cats. Shooting these animals is always a challenge. I have a lot of patience... and pee stories. I was always down on the ground and my knees were wet, my butt was wet, and it was all pee. You gotta roll with it in the trenches."