The light-hearted competition celebrates furry friends which are a common sight at the hospice, providing faithful companionship and bringing joy to patients and their families during difficult times.
Pictures of Christmassy companions will be judged by patients in the Day Hospice, with Joanne Quilter from Paws Pantry in Rustington as chairman of the panel.
The winner will get a bottle of champagne to enjoy over the festive period, so they can drink a toast to their precious pet.
If your pet loves to pose in front of the camera, visit www.stbh.org.uk/petfestive to register and submit your favourite festive photo.
Owners must be aged 18 or over and should send in their photo by midnight on Friday, December 14.
There is a suggested donation of Â£5 per entry to raise money for the hospice's services.