Hi, I have 7 dogs (yes, I know, but 4 were 'dumped' at my farm) and wondering what size/type these would fit? I have a 4 lb Yorkie (yes, dumped...purebred), 6 lb brussels/yorkie mix, 12 lb dachshund (purebred...dumped) and a shih-tzu/poodle mix about 18 lbs. Thank you, Kate f/w :)