While I think that it is true that dogs have evolved to be so cute and appear so loyal that they pull the wool over our eyes and make us think a lot more of them than is probably their due, I also think it is unlikely that they are completely devoid of the emotions of loyalty and love. I am sure that either of my dogs could go to another home and live a happy healthy life with a new family and provide that family with the dog equivalent of love. However that does not mean that they do not have "doggy" love for my family and for each other. Anyone that has seen how sad a animal is when it loses a family member or how happy and proud that animal is with a birth must believe that animals feel love. Just look at the smiling happy face of a momma dog as she sits amist her litter of pups.
What I am saying is that while my dog doesn't love me in the same way I love my husband or kids (ie, if my dog lost me he would not mourn for the rest of his life), I still think that while I am in his life I am very important to him and he would do things for me that might mimack love.