Can Cats Taste Sweet?

Can cats taste sweet?

Cats can’t taste sweet as they lack the necessary sweet receptor necessary to detect sweet, which is referred to as sweet blindness. The sense of taste is perceived via the tastebuds which are located on the tongue. Tastebuds contain receptor cells, which have taste receptors in their membrane. When the cat eats, molecules in the food interact with saliva and bind to the taste receptors of the right shape and convey this information along taste neurons to the brain.

The sweet receptors are generated by two genes known as Tas1r2 and Tas1r3. Researchers at Monell Chemical Senses Center in collaboration with the Waltham Centre for Pet Nutrition, UK found a microdeletion of a DNA sequence on the Tas1r2 gene, resulting in a frameshift that affects how the gene is read, rendering it a pseudogene (nonfunctional segments of DNA that resemble functional genes) unable to make a working protein. Therefore, while Tas1r3 is still functional Tas1r2 is not, and a functional sweet receptor cannot form.  Without a working sweet receptor, the cat cannot taste sweet. Domestic cats are not the only felines affected, this pseudogene affects large cats as well as sea lions, harbour seals, fur seals, Asian otters, dolphins, whales, spotted hyenas, fossa and banded linsang (cat-like animals). The Tas1r2 mutations were different across the carnivores who lack sweet receptors, which suggests that they occurred independently of one another. This phenomenon is known as convergent evolution.

Humans and omnivores who consume a varied diet of meat and plants have five taste receptors:

  • Sweet
  • Sour
  • Salty
  • Bitter
  • Umani (meatiness)

Aside from sweet blindness, the cat’s sense of taste is normal. The inability to taste sweet is not a big deal as cats consume a primarily carnivorous (meat only) diet. Omnivores and herbivores need sweet receptors to detect carbohydrates in plant matter.

Why do cats enjoy sweet treats if they can’t taste sweet?

Cats are known to enjoy an array of sweet foods, especially ice cream. This is due to the fat within the product and not the sugar. If a cat consumes sugar, he or she won’t taste anything at all.

There is a lot of misleading information (even by veterinarians) on the Internet which claim cats are attracted to antifreeze (ethylene glycol) because of its sweet taste but this is not possible. What is more likely is cats are accidentally poisoned when their paws or coat are accidentally contaminated and they consume the toxin during grooming.

If cats can’t taste sweet, what treats do they enjoy? 

While treats should be limited, there are sometimes good reasons to give a cat a treat. Every cat has his or her unique preferences (if any at all). Cheese, poached chicken breast, tuna, fruit and vegetables are all healthy treats suitable for cats, but should only make up 10% or less of a cat’s diet.