Cats cannot taste sweetness — they lost the gene for sweet receptors 25 million years ago
Domestic cats (and all members of the cat family, from tigers to house cats) lack a functional gene for one of the two proteins needed to form the sweet taste receptor. The pseudogene (broken gene) has been confirmed in all tested feline species — they all have the same mutation that disables sweet perception. This makes biological sense: as obligate carnivores, cats have no need to detect carbohydrates. If cats show apparent preference for certain sweet foods, it's due to fat content or other flavour compounds, not sweetness.
Cats are famously indifferent to sweets in ways that puzzle many owners. Finding the genetic reason — that the entire cat family lost this sense 25 million years ago — makes cat behaviour feel less like a quirk and more like a deep evolutionary commitment to being a predator.
“Cats cannot taste sweetness. The entire cat family lost the gene for sweet receptors 25 million years ago. If your cat likes certain 'sweet' foods, it's the fat — not the sugar. 🐱 #OddlyHuman”