The tongue of a cat, like other animals, contains receptors on it. These receptors register different tastes. For example, humans have receptors that lets them distinguish between such tastes as bitter, salty, sour, savory (umami), and sweet.
Cats are the only animal that can’t taste sugar
Cats, including the domestic cat (Felis silvestris catus), are believed to be the only animal that is unable to taste sweetness. The lack of sweetness detection is not limited to domestic cats — wild cat species like lions and tigers also share this trait. This commonality suggests that the absence of sweet taste receptors is a deep-rooted characteristic of the entire cat family.
Researchers encoded the DNA and found that cats lack two genes known to encode the ability to taste sweetness: Tas1r2 and Tas1r3.
Why can’t cats taste sweetness?
Cats are obligate carnivores, which means they require meat for all of their nutrition. Many animals, particularly herbivores and omnivores, utilize sweetness as a signal for energy-rich food sources. The taste of sweetness is an indicator of rich carbohydrates, something absent from the natural animal-based diet of cats.
The genes for tasting sweetness were turned off in cats millions of years ago. The need to sense sweetness is not a necessary function in an animal that doesn’t need to consume high nutrition plants.
Even cats that like to eat cake or ice cream (not something recommended as part of a healthy cat diet) are not eating the desert for its sugar, but attracted to the fat.
Make sure your cat is being feed a high protein diet
Even if you have a cat that will eat foods like cake, grass, or vegetables, it’s important to make sure that these foods make up a very small portion of your cat’s diet. Cats, along with minks, are hypercarnivores and require a high protein diet. Carbohydrates, which includes sugars, should ideally make up less than 10% of their diet.
Cats should never be fed a high carbohydrate or vegetarian-based diet. As cute as it may seem to see your cat licking the frosting off your desert plate, cats require meat or fish as their daily nutritional requirements.
References
Li, X., Li, W., Wang, H., Bayley, D. L., Cao, J., Reed, D. R., … & Brand, J. G. (2006). Cats lack a sweet taste receptor. The Journal of nutrition, 136(7), 1932S-1934S. https://doi.org/10.1093/jn/136.7.1932S
