With more publicity about, regarding too many dogs around for available homes, less people are allowing casual breeding from their dogs these days thank goodness, so not always puppies available straight away. If you just want a cat friendly dog, most of the rescues know which of their dogs have lived with/are good with cats . I expect youve had a look through Freshfields, Dogsblog, Dogs Trust , RSPCA etc . If you want a rescue puppy and you're not looking for a specific breed (but obviously may want to exclude some types and sizes) you stand a better chance of getting one by contacting the rescues and registering your interest . A lot of the time incoming pups get rehomed from a kept list of 'applicants' before getting advertised .Good luck , sounds like one canine is going to be very lucky!