This morning, while I was lying in bed, our cat sat on my chest, purred and licked my face. It's a cute little quirk that I love about him. I know our cat loves me in his unique kitty way.
I've written before about the studies showing that dogs show higher oxytocin levels after they cuddle with their people. And, because people and dogs have the same oxytocin response, you can say that they both feel love. Now, research sponsored by the BBC shows that cats also have an oxytocin response when they're with their people -- it's just not as strong.
Oxytocin levels went up 12 percent in cats after they played with their owners. Oxytocin levels in dogs went up 57.2 percent. So, you could say that your dog loves you five times more than your cat. Hey, we know dogs are easy.
There is something I would add, based on my personal experience. Oxytocin levels go up during positive social interactions. It's a function of being comforted/comfortable. I would bet that cats' attachment to their owners is not as strong as dogs'. That is, the oxytocin response is more tightly connected to social memory in dogs than in cats. Just my personal theory.
Read the article in Bustle: http://www.bustle.com/articles/138786-dogs-love-their-owners-more-than-cats-do-but-that-probably-doesnt-surprise-you