[hueyeats]

I think if OP insists on keeping them outside, OP would be more humane to re-home your pigs.

I do not think it would be fun for them (piggies) when they have to live in constant fear of being food to that cat or some other animals. I do not think as a human you would enjoy living in constant fear of losing your life (eg. when you live in a crime filled neighbourhood where you run the chances of being shot at)... your piggies won't enjoy that too (even if they have unlimited supplies of food; without life & safty, what is the use of food?).

Re-homing would also be more humane of a treatment to your dog & your neighbour's cat (so you do not have to spray at it or leave your dog to freeze; which I am also sure that your poor piggies are freezing too as they like human temperature zones).

Yeah, rehome your pigs if you cannot have them inhouse... best option.