Petzarus.com

Taste receptors for sweet flavors developed in order for omnivorous species like humans to be able to sense plants and fruits that would provide a rich supply of carbohydrates and sugars, which our bodies metabolize in order to create energy. As obligate carnivores, cats have no need for, and can’t digest and process, carbohydrates, so evolution eventually deleted the gene for the sweet tooth.

Studies say that dogs can learn up to 100 languages and gestures. And in addition, dogs are much easier to train as compared to a two-year-old.