Patch was signed over into the centre's care when his owner died and the rest of the family was unable to take care of him.
He’d been kept locked in a porch without much food or exercise.
He was also underweight and covered in urine stains.
RSPCA behaviour advisor Hannah Hawkins said: “We spent a lot of time getting to know him and helping him learn about the big wide world.
“We were so thrilled when he found a new home over the summer but, after just a few hours, his owners returned him because he was too strong and boisterous for them. We were all gutted.”
Big Patch is a lovely, clever dog who is very playful and needs owners who can give him lots of exercise and keep him occupied.
He knows lots of commands like ‘sit’ and ‘paw’, and he responds well to his name although he can be a bit strong on the lead when he gets excited!
Hannah added: “Big Patch can be aloof when he first meets people but it doesn’t take long for him to warm up to you and then he soon leans in for a fuss. With his friends, he loves nothing more than a cuddle.
“We’d like to find him an active owner who can keep up with him and ideally it’ll be someone with experience with large breeds who understand what it means to take them on.
“We think someone who is patient and will be able to work with him as he transitions into life in a home will be best. With good guidance, Patch will make the most wonderful companion - he just needs some time to adjust after such a tough start.
“We’d love to find someone local who can visit Big Patch and get to know him, and so we can provide support as he settles in.”