Cats and dogs: members of kingdom Animalia, popular domestic pets, subjects of common rain-based euphemisms. And though they share some similar traits (like fur!) they are decidedly different beasts when it comes to eating habits. Now, science claims to have figured out the particulars of this discrepancy. Because that's what science does, nowadays.
Freshly researched... um, research... has determined that kitties posses the ability to taste bitter flavors, normally reserved for vegetarian animals (cats are obligate carnivores, which means they swing both ways on the food chain, out of necessity). The bitter taste receptors have been part of vegetarian's evolution, as it helps the animals determine if a plant in question is poisonous, just as sweet taste receptors are present for animals to find energy-giving (and delicious) sugars within foods. However, geneticists have also determined that dogs' tongues are equally graced with the bitter buds -- so what's the difference between, them, really?