photo by zaser
Cats cannot taste sweet food because a gene (symbol Tas1r2) that normally controls the ability of the receptor that should detect and send signals to the brain for sweet tasting food is defective and the gene is in fact what is called a Pseudogene. The scientists call this gene an "unexpressed pseudogene".
Domestic cats do not react in a positive or negative way to sweet carbohydrates (sucrose and other sugars), i.e. they fail to respond. In other areas of taste the domestic cat is it seems the same as other mammals including humans and dogs, for example.
Testing indicated that a gene (see above) was in fact non-functioning as it was, in fact, a Pseudogene. This meant that the taste buds and detectors in the tongue for sugars do not transmit signals to the brain.
In contrast dogs prefer natural sugars such as sucrose. An animal's choice of food is to a certain extent dictated by the taste receptors. As cats cannot taste sweet food they have no preference for it. Dry cat food contains carbohydrates which are required to make the manufacturing process function. The carbohydrates are not in the food to make it more attractive to cats. That is achieved by the addition of meat digests.
Cats cannot taste sweet food to cat food recipe
This short post is my summary (and additional thoughts) of a longer research article on this subject published at PubMed Central. The full URL of the article is this:
Cats cannot taste sweet food - Photo: published under a creative commons license - Attribution-NonCommercial-NoDerivs License