She’s written hits for the Pussycat Dolls, but Keri Hilson nearly had a cat fight with an assistant at a Las Vegas gig Saturday, sources say. After performing her hits “Pretty Girl Rock,” “Turnin Me On” and “Knock You Down” to a crowd at Haze at the Aria Resort and Casino, Hilson came off stage and realized that her aide hadn’t removed a tag from the black harem pants she was wearing, spies said. “Hilson lost it,” one source said. “She was screaming at her assistant for ‘not being able to do anything right.’ [She] railed that the assistant also forgot to ‘pack her eye drops and throat spray.’ ” The peon didn’t respond kindly, saying, “Oh, hell no!” and Hilson’s security guard and manager intervened before the pop star, touring with Lil Wayne, stormed off. Hilson’s rep told us, “Keri did ask her assistant to bring her eyedrops/throat spray as she was feeling under the weather, but there was no altercation. Keri has had the same road staff, from assistant to security, for a few years now.” After the show, Hilson Tweeted, “Shout out to all the PARTY PEOPLE at HAZE tonight!!!! Much love to promoter, mgr & staff for takng great care!!”