Charlotte Speedy joined as head of communications this week after nine years in agency PR, including a stint at Bell Pottinger.
'I love dogs. It will be great to get my teeth into something I care about,' she said.
Dogs Trust - known for its slogan 'A dog is for life, not just for Christmas' - is the UK's largest dog welfare charity, caring for more than 16,000 dogs a year through its 17 rehoming centres.
Speedy reports to chief executive Clarissa Baldwin.