Bloomberg: A drought in northern China that has limited drinking water to almost 4 million people may also be making birds more susceptible to the deadly H5N1 avian-flu strain. The lack of rainfall in Shandong, Shaanxi and other northern provinces since October causes stress for local fowl, said Hong Kong Veterinary Association President Veronica Leong, who specializes in birds. “Any sort of stress would make birds more susceptible to disease,” she said by e-mail today. Bird flu killed …