[Seemingly] the dog and its owners

I've heard that lovers' appearances will be closer and more similar as they spend long time together(in 2.5 years, why I am still so dark while she is still so fair). However, if animals and their breeders also follow this rule, it would be quite funny. It is unclear whether dogs will be more and more like their owners or the owners become more and more like their dogs... I can't tell...