Grayling UK chief executive Amanda Riddle heads the team and reports to Battersea Dogs Home director of public affairs Helen Tennant.
The agency's remit is to promote the relaunch of the charity's website and support other in-house PR initiatives.
'The brief also includes the annual summer London-wide campaign to ensure pet owners provide proper care during their holidays. We will also work to promote the rising number of cats at the sanctuary,' said Riddle.
'The home is now a famous global brand and the demands on our four-strong in-house team were increasing,' said Tennant.