This week the IPA announced Specific Media had the best customer service of online media owners for the seventh consecutive period, in its annual survey of media agencies.
It is not known whether Dowds will be directly replaced or whether he has a job to go to.
Dowds joined Specific Media from the Turner Media-owned ad sales house Turner Media Innovations (TMi) in February 2009. At TMi from May 2005, Dowds was promoted from group account director to sales director.
As sales director at TMi, Dowds was in charge of advertising, sponsorship, online and new-media revenue across the company's channel portfolio including Cartoon Network and Cartoonito.
Prior to joining TMi, Dowds was a managing partner at WPP ad agency Mindshare between February 2001 and May 2004. He started his career at ITV sales house TSMS in 1991, rising to account director by 2000.
Dowds declined to comment. A spokeswoman for Specific Media declined to comment.