Turns out the source was from this interview (and no mention of ratting - my mistake - which perhaps makes it weirder)
https://www.toniachristie.de/interviews-2021/raynor-winn-the-salt-path/
How did your dog Monty come into your life?
The way I talk about dogs and dogwalkers in The Salt Path you wouldn’t think I would ever have a dog, would you? [we both laugh]. We went to this Farm for some reason and the owner had this little tiny puppy in a cage in the back of his shed. He had sold all the others, they were twice the size of him and nobody wanted him because he’s got wonky legs, funny little bent legs. His back legs are perfect, but his front legs look like little Cabriole table legs. [we both laugh] And the owner said if he’s not gone by Friday he’s in a bucket, and he was going to drown him. And we said – no you can’t do that! So we went home with a puppy. We hadn’t even considered having a dog or a puppy, living in that one bedroom apartment in Polruan with no garden and we thought – what have we done? He’s turned out to be the most surprising little addition to our family. He’s very small and with his wonky legs he couldn’t come on this big walk with us this year, cause it would have been too far for him. He’s a very happy little dog who plays endless football with his tennis balls.