A dentist's dream come true: Some carnivores lack a sweet tooth

New research conducted by Dr. Gary Beauchamp from the Monell Chemical Sciences Center in Philadelphia has shown that seven of twelve species of carnivorous mammals tested lack taste receptors for sweets. According to the article, Dr. Beachamp and his colleagues identified mutations in the mammalian taste receptor for sweets (Tas1r2/Tas1r3) in animals from the Pinnipedia order (sea lions, fur seals and Pacific harbor seals), bottlenose dolphins, Asian small-clawed otters, Spotted hyenas, fossa (member of the mongoose family), and cat-like banded linsangs. In contrast, normal sweet receptors were found in the carnivorous aardwolf, Canadian otter, spectacled bear, raccoon and red wolf. In functional studies, animals with mutated Tas1r2 had no preference for sugars (Asian small-clawed otters) whereas animals with intact taste receptors exhibited strong preferences for sweets (spectacled bears). Since the types of mutations varied between each of the species, this suggests that the loss of taste receptors for sweets independently evolved multiple times in carnivores.

These cats, however, clearly have intact taste receptors for sweets:
Image Source: www.seriouseats.com

Jiang et al., Major taste loss in carnivorous mammals. Proceedings of the National Academy of Sciences. Epub Ahead of Print.

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I had been told that cats did not taste sweet, but then I got a cat and discovered that observation trumped dogma. (My cat also loves garlic mashed potatoes. Has no-one informed her that she's a carnivore?)