I do agree with dan here, Connemmara. Although there is no way in hell my dog would live outside, I suppose as long as his "pets" are sheltered and fed, he is well within the law.
Are they muzzled to stop them catching smaller furries?
Are they kept warm in Winter and cool in Summer? This is very important for greyhounds.
Some people view dogs in entirely the way you describe, but for me I wouldn't have a pet who I couldn't share my house/sofa with.
I can't imagine how the dogs feel about it, but I suppose if there's 3 of them, they have their own company at least.