One’s smaller than a bag of sugar and the other’s as heavy as a full-grown woman - but that hasn’t stopped these two pets becoming best friends.

Digby the tiny chihuahua, who weighs less than 1lb, was close to death when he was rescued from between two rubbish bins outside a block of flats in north London. But since being taken to an RSPCA centre he has a new reason to survive - in the form of nine-stone Neapolitan Mastiff Nero.

The pair have become inseparable at the centre in Southridge, Hertfordshire, despite giant Nero eating the weight of four Digbys in dog food every day. Centre manager Anna White said: ‘It was as if the little fellow took on Nero as his personal minder.

‘Poor Digby had to be rescued once by the RSPCA and it seems like he is taking precautions to make sure nothing can happen to him again.’

Digby was found severely dehydrated and cowering between two bins on Monday night. The RSPCA is appealing for information in a bid to trace his owner. Unless an owner comes forward, Digby will be available for rehoming in the next few days. Natalie Ditchfield, RSPCA animal collection officer, said: ‘It is so lovely to see he is safe and happy. ‘When I first came across Digby he was frozen and shaking and had just been left to die. He’s really tiny - small enough to fit in the palm of my hand. ‘He seemed to come out of his shell as soon as we arrived at Southridge and spotted Nero. It really is a love story.’