Dreamworks Animation SKG Inc. reported a 65 percent drop in net income for the first quarter when compared with a year earlier even as the Glendale-based animation studio rides the box office success of its latest film, “How to Train Your Dragon.” The 3D animated feature has grossed nearly $375 million to date in worldwide box office receipts. A sequel is planned for release in 2013, said studio CEO Jeffrey Katzenberg. For the quarter ending March 31, DreamWorks Animation reported net income of $21.7 million, or $0.24 per diluted share, on revenues of $162.1 million. For the same period in 2009, the company had net income of $62.3 million, or $0.71 per diluted share, on revenues of $263.5 million. The better results for the first quarter in 2009 can be attributed to international box office and home entertainment sales for “Madagascar 2: Escape to Africa, which brought in $147.5 million in revenue, and international home entertainment sales of “Kung Fu Panda,” which had brought in $34.1 million. Nearly $60 million in revenue for the 2010 first quarter came from “Dragon,” primarily from merchandising and licensing activities, with domestic pay television sales of “Monsters vs. Aliens” adding another $24.6 million. “Dragon” hit theaters just six days before the end of the quarter.