Oddly enough, the only other domestic animals that have raspy tongues are the vegetarian cow and its relatives. While we know quite a lot about the structure of the feline tongue, we know considerably less about its tasting abilities. After all, your cat can't tell you whether it perceives something as sweet, sour, or bitter. Nevertheless, scientists have tried to assess the gustatory sensitivity of cats by training them to discriminate between plain water and water mixed with sugar, salt, or some other substance. The results of these taste tests suggest that cats can detect sour, bitter, and salty tastes, but not sweet ones.
Cats appear to be sensitive to the taste of water itself.
While humans generally consider water to be tasteless, cats show a high sensitivity to natural variations in water flavor. This may explain why certain cats are picky in their drinking habits. Our family cat, Kelly, will only drink running water from the tap. Many people say their cats show a district preference for sweet foods like ice cream, cookies, and fruit. For example, the desire for ice cream , may be due to its iciness and creaminess - not its sweetness.